Linux

Linus Torvalds began writing the Linux kernel in 1991. The kernel alone is not a desktop. A distribution adds commands, package management, and often the GNU tools to the kernel. Ubuntu, Debian, and Fedora are separate distributions. All of them run the Linux kernel, but their packages and install path are not the same. Android also uses the Linux kernel. Android is not Ubuntu.

Linux is chosen on a server, in the cloud, and on a small device. Staying up for a long time and being set up with packages is its ordinary place.

• A site server
• The system inside a container
• Network equipment
• The kernel of an Android phone

With Linux you see a process, install a package, split a disk, and open or close the network. It does not draw the page itself. Nginx, a database, and your program draw the page. A command without care can break a system file. The root user can change everything.

Installing a package is easy. The difficulty is permission and the service. If a file does not belong to your user, the command stops. When a service falls, the page falls too, even though the kernel is still running. Mixing up distributions sits here as well: an Ubuntu command may not work on Fedora under the same package name.

Advantage: it is widely used on servers, packages are clear, and the kernel's code can be read. Limit: not every desktop program is ready here. When a command is wrong, undoing it is harder than in a window. Linux is not the same word as Ubuntu.

The kernel talks to the hardware. A distribution is the ready system around that kernel. A package is a program tied up for install.

• The kernel divides a process and memory
• A distribution keeps packages in one place
• A service runs in the background
• A permission says who may change a file

This command shows the short name of the kernel that is running. It does not install the system and it does not delete a file.

uname -r

• Are Linux and Ubuntu the same? No. Linux is the kernel. Ubuntu is one distribution that runs that kernel.
• Is Linux a programming language? No. It is the system programs run on.
• Is Android Linux? Android runs the Linux kernel. It is not Ubuntu or a desktop Linux.