Lesson 1.1: What is Linux?
Hardware, software, operating system and kernel; where Linux came from (Unix, GNU, Linus Torvalds) and why it runs most of the world's servers. Lab: ask the kernel who it is with uname.
15 min
You will learn to
- Define hardware, software, operating system and kernel
- Explain what 'Linux' strictly means (the kernel) and what GNU/Linux adds
- Explain open source and the GPL in one sentence each
- Read the output of uname, uname -r and uname -a
Key terms
- Hardware
- The physical parts of a computer: processor (CPU), memory (RAM), disk, network card, screen, keyboard.
- Software
- Instructions that tell the hardware what to do. Programs, apps and the operating system are all software.
- Operating system (OS)
- The software that manages the hardware and lets other programs use it safely and in turn: it decides which program uses the processor, how memory is shared and how files are stored.
- Kernel
- The heart of the operating system: the program that talks to the hardware directly and runs all the time. Other programs ask the kernel when they need the disk, the network or memory.
- Driver
- A piece of the kernel that knows how to talk to one kind of hardware, for example a specific network card.
- Unix
- An operating system created at Bell Labs in 1969. Its ideas (everything is a file, small tools combined together, multi-user) shaped Linux and macOS.
- Linux
- Strictly, a kernel: the one Linus Torvalds started in 1991 as a hobby project and that thousands of developers now maintain. In everyday speech 'Linux' means a whole operating system built on that kernel.
- GNU
- A project started by Richard Stallman in 1983 to write a free Unix-like system. It produced most of the basic tools you'll type every day (bash, ls, cp, grep).
- Open source
- Software whose source code (the human-readable program text) is published so anyone can read, change and share it under its licence.
- GPL
- The GNU General Public License, the licence of the Linux kernel: you may use and change the code, but if you distribute a changed version you must publish its source code too.
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