What is Unix?

An operating system that is multitasking and multi-user. Designed for servers, workstations, and mobile devices. It has a modular structure, a powerful command shell, and a wide range of utilities. It adheres to the open standard POSIX.

Main features:

• Multitasking: Allows multiple programs to run simultaneously.
• Multi-user: Several users can work in the system at the same time.
• File system: Hierarchical directory structure.
• Command line: A powerful interface for interacting with the system (e.g., Bash, Zsh).
• Utilities: A set of standard programs for various tasks (e.g., ls, grep, awk).
• Pipelines: Ability to redirect the output of one command to the input of another.
• Sockets: Mechanism for inter-process communication.

Examples of commands:

# View directory contents
ls -l

# Search for strings in a file
grep "pattern" filename

# Run a script
./script.sh

Examples of distributions:

• Linux (Ubuntu, CentOS, Debian, etc.)
• macOS
• Solaris
• FreeBSD