Linux vs Unix

The key difference between the Unix and Linux-based operating systems lies in how they work internally, especially at the kernel part. Read along to find out the exact differences between the two.

Updated: 29 Dec, 24 by Susith Nonis 20 Min

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The Linux operating system is often described as a "UNIX-like" one. However, many users don’t have enough information about Unix! Linux operating system has many similarities to UNIX in terms of design and functionality but is not a UNIX operating system. UNIX is a registered trademark and a proprietary program owned by The Open Group. On the other hand, Linux is an open-source operating system that was developed as a free software alternative to UNIX. The difference between Linux and UNIX doesn’t end there. In this blog post on MonoVM, we will give you a detailed explanation of Linux vs Unix, examine their features, and their differences. Let’s start with their basic introduction.

Unix is ​​a multi-user operating system that allows more than one person to use computer resources in real-time. Because Unix allows you to communicate directly with a computer through a terminal, it is a very interactive operating system that gives you direct access to resources. You can also share data and programs with other users. Unix uses a hardware system that includes large memory, a 32-bit processor, and fast, large hard disks. The Unix operating system is suitable for many types of machines and computers, including personal computers, because it is written in a machine-independent language (C or C++). For this reason, Unix can be adapted to meet the specific needs of a variety of devices.

History of Unix

Compared to Linux, Unix can be considered a dinosaur of operating systems, developed in the 1960s by Bell Labs employees. In the years following the release of the source code for the original Unix, various branches of this operating system were released. The BSD and System V operating systems are two of the Unix family's most well-known and widely used versions. Although the two groups of BSD and System V initially had more differences, these differences have gradually faded. By adopting innovations from competing operating systems, the operating systems of both groups have become closer in terms of performance and technology. The macOS X operating system is one of the most well-known operating systems developed based on the BSD family.

Unix key features

With its high-security capabilities, proper management, and portability, Unix is ​​known as one of the most stable and oldest operating systems in the world. Currently, many Unix distributions, including Linux, macOS, and Solaris, are used on large computers and servers. The Unix system comes with the following characteristics.

  • It uses plain text for storing the data.
  • It has a hierarchical file system.
  • It can handle various devices and some particular inter-process communication (IPC) in files.
  • It is capable of employing a massive amount of software tools.
  • It consists of thousands of small, simple, and modular programs that can be connected with the help of the command-line interpreter via pipes.

Unix use cases

Unix is ​​designed to support multiple simultaneous users and network services. This operating system is widely used in:

  • Industrial purposes 
  • Scientific purposes
  • Research
  • Educational purposes
  • Many internet servers 

Unix Architecture

The diagram below will explain the architecture of the Unix.

[image source]

The kernel is the core program of the Unix operating system that has complete control over the entire system. It comes with various subsystems responsible for handling the files, resources, and memory. Also, they will take care of the start and stop of the programs and other low-level tasks. The kernel is considered the heart of the OS and acts as an interface between the underlying hardware and the applications that are running on top of it. The kernel subsystems come with exceptional features such as concurrency, virtual memory, and VFS. 

As per the above image, the outer layer of the Unix architecture contains the shell, commands, and application programs. Here, the shell acts as an interface between the user running the system and the kernel inside the system. Users run the commands on the shell and interpret them in the language understandable by the kernel and then the required computer programs as per the given command.

Linux is an open-source Unix-like operating system designed for a variety of devices, including computers, servers, and mobile phones. It is a Unix-like operating system as it has most of the functionalities and features of Unix. Linux is one of the stable OS examples of the Unix derivates. It is supported on almost every computer platform, including x86, ARM, and SPARC, making it one of the most widely used operating systems. Each version of the Linux operating system provides a user interface for managing hardware resources and launching and managing applications. 

Are you looking for a strong and adaptable server for your company? If you said "yes," a Linux server is a good choice.

History of Linux 

Linus Torvalds designed the Linux operating system. He initially worked on the UNIX operating system (proprietary software) and believed that it needed changes and improvements. However, when the designers of UNIX rejected his suggestions, he thought of creating an operating system that would be open to changes suggested by users. For this reason, in 1991, Linus Torvalds designed a kernel called Linux; although it needed programs such as file managers document editors, and audio and video programs to run. Over time, Linus Torvalds collaborated with other programmers at places such as MIT and designed applications for Linux. In that year, the Linux operating system was officially launched with some programs. Early versions of the Linux operating system were not as user-friendly as computer programmers used. Torvalds never intended to commercialize his product. This reduced the popularity of Linux as other commercial operating systems such as Windows became popular. However, the open-source aspect of Linux made it stronger.

You may want to know the best Linux VPS providers in 2024

Linux key features 

Like Unix, Linux is a multi-user, multi-tasking operating system, and like Unix, Linux is implemented primarily in the C programming language. Linux is compatible with a wide range of processors and hardware and is suitable for multi-processor systems. In terms of such technical features, the differences between Linux and Unix are minimal. Some key features of the Linux operating system include:

  • Open Source: Free to alter and distribute.
  • Multitasking: Capable of executing multiple processes at once.
  • Security: Robust user permissions and integrated security features.
  • Stability: renowned for high uptime and dependability.
  • Customizability: Highly configurable, from the kernel to the user interface.
  • Community Support: Comprehensive documentation and active community-driven support.

Linux use cases 

Linux is an open-source and flexible operating system that has been successfully used in a variety of applications. One of the main uses of Linux is in the world of Internet servers, where Linux systems are used as a popular platform for providing hosting and other network services due to their stability, security, and reliability. Other use cases of Linux include:

  • Hosting and network services 
  • vacuum cleaners
  • welding machines
  • network equipment
  • smart devices
  • Developers and system administrators

Linux Architecture

[image source]

Linux system has monolithic and microkernel structures. If Linux supports the monolithic kernel structure, there is only the kernel space where every task will occur. At the same time, if the system is a microkernel, the system has separate userspace and kernel space, as shown in the above image. Userspace will consist of the libraries, system daemons, shells, and the required tools for running the applications. The kernel space will consist of the schedulers, drivers, security, and networking that will help manage the system resources so that the resources will be available to all the running applications simultaneously without impacting the working of all applications.

Linux

Unix and other Variants

Linux operating system will refer to the GNU/Linux operating system kernel. 

Unix is the original operating system that was developed by AT&T. 

The original code of the Linux operating system was developed by Linus and the GNU Foundation

The original code of the UNIX was developed by AT & T

The trademark of the Linux operating system is owned by Linus Torvalds and managed by the Linux Mark Institute.

The UNIX trademark is certified by the Open Group. 

Linux has derivates such as Debian and Fedora

UNIX has derivatives such as FreeBSD and macOS

Linux is available as an open Source under the copyleft General Public License

Berkeley Unix comes as a partially open-source under the BSD License while on the other hand, the System-V Unix source is procured under a proprietary commercial license.

Different variants of the Linux OS is maintained by different communities; along with the kernel that is merged into the branch maintained by Linus

Different variants of the UNIX OS is maintained by various companies, and each of them maintains their kernel

Linux OS was designed as a general-purpose and scalable platform that is capable of running various applications.

UNIX OS was basically designed for a small audience who wants to work with a defined set of target platforms and applications.

Linux OS is mainly available as a configurable software download and installer.

UNIX OS is typically shipped along with the hardware e.g. MacBook

It comes with free and huge community support. You can also avail of its paid support available from several service providers.

You can only avail of its paid commercial support which might lead to a vendor lock-in situation.

Linux comes with interfaces that often evolve

UNIX comes with interfaces that are usually stable

You will get frequent updates that come with quick bug fixes

You will not get frequent updates, thus making bug fixes late.

It comes with support for almost all file systems and can be used across operating systems

Unix OS mostly comes with support for two or perhaps three file systems

It is one of the preferred OS that is available for cloud deployment and data centers 

It is mostly the preferred OS for special-purpose server requirements 

It is highly scalable and its scalability can be achieved using clusters, grids, or cloud.

The scalability of the UNIX system can be achieved using clusters or grids

Features

Linux

Unix

Developer

Inspired by Unix-like OS, Linux was originally developed by Linus Torvalds. It is available as an open-source and comes with a huge community of developers for Linux.

Originally developed at Bell Labs by Kenneth Lane Thompson, Dennis Ritchie, and 3 others.

Written in

C and other programming languages.

C and assembly language.

OS family

Unix-like

Unix

Working state

Current

Current

Source Model

Open-source

Mixed. Traditionally closed source, but some are available as open-source including illumos OS and BSD OS.

Available in

Multilingual

English

Initial release

First released in September 1991.

First released in October 1973 for outside parties but internally it was developed in Bell Labs since its inception in 1970.

Kernel Type

Monolithic kernel

Kernel Type may vary and can be monolithic microkernel or hybrid.

License

GNUv2(GPL General Public License) and others.

Licensing may also vary. Some of its versions are proprietary while others are free/OSS.

Official Website

https://www.kernel.org/

http://opengroup.org/unix

Default user interface

It has a Unix shell

It has CLI (Command Line Interface) and Graphical (X Windows system)

Text Mode Interface

By default, the shell works as the  BASH (Bourne Again Shell) which is compatible with various command interpreters.

Originally the Bourne shell was compatible with various command interpreters.

Cost

Can be obtained and used freely. You can also avail of the priced versions of Linux as well. 

Prices may vary according to the vendors selling them.

Architecture

Was created for Intel's x86 hardware

Compatible with PA and Itanium machines. Solaris is also available on x86/x64. OSX is PowerPC.

The advantages of Unix include:

  • High stability: Unix is ​​highly stable due to its proper design and rarely stops due to a crash or error in the system.
  • High security: Unix provides high security for the system by having limited user access levels and secure commands and processes.
  • Command line environment: Unix uses a command line environment (Command Line Interface), which is very attractive to professional and powerful users.
  • Extensibility: Unix is ​​very attractive to developers and programmers due to its Open-Source architecture and high extensibility.
  • Network support: Unix is ​​very powerful in establishing network communications due to its support for network protocols such as TCP/IP for communication with other servers and the Internet.
  • Support for extensive programs: Unix is ​​very attractive to developers and programmers due to its ability to support extensive programs and many programming languages.
  • High performance: Unix is ​​highly efficient due to its proper design. It has high performance against heavy loads and large data volumes.

There are also some disadvantages with Unix which include:

  • Support and maintenance of the system: You need high technical knowledge to support and maintain it. Also, system support may require high technical knowledge.
  • Need for special commands: Unix has interaction problems for some users due to the need for special commands and requires learning special commands. This may cause problems for users who are not familiar with working with Unix.
  • Hardware limitations: Unix requires powerful hardware due to processing large data, and this limitation may prevent some users from using it.
  • Need for time and cost to learn: Unix may be difficult for users who are beginners. Also, it requires cost and time to learn it.
  • Problems with existing applications: Unix doesn’t support some applications available on other operating systems, and this may cause problems. 

Some of the advantages of using Linux include:

  • Open-source software: The Linux kernel is released under the GNU GPL open-source software license. Most distributions include hundreds of applications, with many options in almost every category. 
  • Licensing fees: Unlike Microsoft Windows or Apple macOS operating systems, Linux has no licensing fees. While system support is available for a fee from many Linux vendors, the Linux operating system itself is completely free to copy and use. 
  • Reliability: Linux is a reliable operating system and is well-supported with security protocols. Linux is also considered a stable operating system, meaning that it can run without problems in most situations.
  • Backward compatibility: The configurations and shell scripts in this operating system remain unchanged, even when software updates are applied. In this way, the operating system is backward compatible with all its previous versions and its applications.
  • Multiple choices: Hundreds of different distributions, thousands of applications, and countless options for configuring, compiling, and running Linux on any hardware platform have made it possible to optimize Linux for any application.

Along with these advantages, the Linux operating system also has several disadvantages, including:

  • Lack of a defined standard: There is no standard version of Linux that is provided to optimize Linux for running specific applications. As a result, using this operating system can be complicated in some cases.
  • Support costs: While an organization or individual can purchase Linux for free and without a license fee, its support is not free. Most enterprise Linux distributors, such as SUSE and Red Hat, offer support contracts. Depending on the circumstances, these license fees can be quite hefty.
  • Proprietary software: Proprietary desktop software such as Microsoft Office cannot be used on Linux computers. Also, there are other similar software that don’t run on Linux.
  • Unsupported hardware: While many hardware manufacturers make Linux drivers available for their products, others only provide drivers for the Windows or Mac version.
  • More difficult to learn: Many users have difficulty learning to use the Linux desktop or Linux-based applications.

It is good for you to know what is Kali Linux

Generally, we can say Linux is a better choice for modern use cases. Today, many users look for features like flexibility, cost-effectiveness, and wide application across various platforms. So, for these purposes, Linux is a better choice. But before choosing, it’s a good idea to consider the following factors:

Choose Linux if:

  • You want a more budget-friendly choice. 
  • You care about flexibility and customizability. 
  • You want an open-source nature to be used in a wide variety of applications.
  • You need community support.
  • Security and reliability are important factors for you. 

Choose Unix if:

  • You want heavy data loads, scientific computing, and industrial applications.
  • You or your team are comfortable with the command-line interface and need fine-grained control over systems.
  • You need strong network communication capabilities for large-scale environments. 
  • You have enterprises with legacy systems and large, powerful hardware. 

It may be interesting for you to get to know some real-world applications of Linux vs Unix. Here are some of the most famous industries that use Linux:

  • Web Servers: Apache, Nginx, LiteSpeed 
  • Hosting and Cloud Services: Amazon Web Services (AWS), Google Cloud, and Microsoft Azure 
  • Mobile Devices: Android OS 
  • Network Devices and Routers: Linksys, Netgear, and TP-Link.
  • Software Development: Git, Docker, and Kubernetes. 
  • Data Centers: Red Hat Enterprise Linux (RHEL) and CentOS 
  • Video Editing and Graphic Design: Blender (for 3D modeling) and Kdenlive (for video editing) 

You may want to know the best Linux web browsers

There are also some famous enterprises which use Unix, including:

  • Enterprise Servers: AIX (IBM), Solaris (Oracle), and HP-UX (Hewlett-Packard)
  • Mainframes: IBM z/OS (a Unix-based operating system)
  • Web Hosting: Solaris and AIX
  • Database Management: Oracle Database

Conclusion

Unix is ancient and is the base for other operating systems. Linux kernel also comes from Unix. The key difference between the Unix and Linux-based operating systems lies in how they work internally, especially at the kernel part. One significant difference you can consider is that Linux is available as an open-source and allows other developers to change the source code, which is impossible with Unix OS. If you choose between the two, pricing can be considered a deciding factor, as you have to pay for using Unix OS, which is not always the case with Linux OS. 

If we talk about flexibility, Linux is more flexible; that’s why it is more popular and used than Unix OS. Also, Unix and Linux commands are somehow similar but not the same. The decision lies in the purpose of using them, and the choice may vary accordingly.

Linux is an open-source, free operating system, while Unix is a proprietary OS owned by The Open Group.

No, Linux is not directly derived from Unix but is considered "Unix-like" due to similarities in design and functionality.

Linux is more user-friendly, offering graphical interfaces and extensive community support, whereas Unix typically relies on command-line interfaces.

Yes, most Unix programs can run on Linux due to its Unix-like environment, though minor compatibility issues may occur.

Linux is preferred for modern servers due to its scalability, flexibility, and cost-effectiveness, while Unix is used for specialized high-stability tasks.

Linux is open-source and free under the GNU GPL, while Unix requires paid licensing from vendors.

Susith Nonis

Susith Nonis

I'm fascinated by the IT world and how the 1's and 0's work. While I venture into the world of Technology, I try to share what I know in the simplest way with you. Not a fan of coffee, a travel addict, and a self-accredited 'master chef'.

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Vella Pouros

2024, Sep, 24

This article does a fantastic job of breaking down the differences between Unix and Linux. I appreciate the detailed comparison, especially the insights into their architecture and kernel structures. It's clear that both have their unique strengths, but it's fascinating to see how Linux has evolved from its Unix roots while providing flexibility and open-source benefits. The tables and diagrams make it easy to understand complex concepts. Great read for anyone looking to understand these operating systems better!

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Anabel Reinger

2024, Oct, 24

This post does an excellent job at highlighting the differences between Linux and Unix, especially in regard to their development and architecture. It's fascinating to see how Linux, while being a Unix-like system, has carved its own niche due to its open-source nature and community-driven support. The detailed comparison makes it clear how flexibility and cost can influence a user's choice depending on their specific needs. Great read for anyone exploring these operating systems!

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Tressa Rolfson

2024, Oct, 24

This article does a fantastic job of diving into the intricacies of Unix and Linux, highlighting their distinct features and shared heritage. It's insightful to see how Unix laid the groundwork for various operating systems, while Linux's open-source nature makes it a flexible choice for many. The detailed breakdown of each system's architecture and kernel approach is especially useful for both beginners and seasoned tech enthusiasts. A must-read for anyone interested in OS development!

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Dr. Roderick Barrows DVM

2024, Nov, 24

Great read! This article does an excellent job of diving into the intricate details between Unix and Linux. It's fascinating to see how Linux, inspired by Unix's structure, has evolved into a flexible and open-source powerhouse. The comprehensive breakdown of both operating systems' features and histories really clarifies their individual strengths and applications. This is a must-read for anyone curious about the backbone of modern computing systems and their development!