What is Linux?
Linux is a free, open-source operating system that powers most servers, phones and cloud infrastructure.
Linux is an operating system — the software that manages your computer's hardware and lets programs run. Like Windows or macOS, it sits between you and the machine.
Why learn Linux?
- The vast majority of web servers and cloud machines run Linux.
- Android, most smart devices and supercomputers are built on it.
- It is free and open source — anyone can read, change and share the code.
- Developers and DevOps engineers use its command line every single day.
Technically, "Linux" is the kernel — the core created by Linus Torvalds in 1991. When bundled with tools and applications it becomes a full distribution such as Ubuntu or Fedora.
Example
# Ask the system which operating system you are running
uname -o
# Output: GNU/Linux
# Show detailed distribution information
cat /etc/os-releaseWhen to use it
- A startup chooses Ubuntu Server for its web application because Linux runs 96% of the world's top web servers.
- A DevOps engineer uses Linux containers (via Docker on a Linux host) to deploy microservices consistently across dev, staging, and production.
- An Android app developer traces system crashes by reading kernel logs on a Linux-based device using 'dmesg'.
More examples
Identify OS and kernel
Shows the operating system name and running kernel version.
uname -o
# GNU/Linux
uname -r
# 6.8.0-45-genericRead full distro metadata
Reads the standardised release file that all modern distros provide.
cat /etc/os-release
# NAME="Ubuntu"
# VERSION="24.04.1 LTS (Noble Numbat)"
# ID=ubuntu
# ID_LIKE=debianCheck uptime and load
Reports how long the Linux system has been running and its current CPU load averages.
uptime
# 14:23:01 up 42 days, 3:07, 2 users, load average: 0.12, 0.08, 0.05
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