Repository

We learned basic Bash built-ins and GNU utilities. These tools are installed on the Unix environment by default. It can happen that they cannot solve our task. In this case, we should find an appropriate program or utility and install it on our own. Installing software on the Unix environment is not the same as installing it on Windows. Let’s have a look at how to install and update the software on any Unix environment or Linux distribution properly. Whenever we install the software on the Unix environment, we should use a repository. A repository is a server that stores all available programs. These programs are prepared by maintainers. Maintainers are persons who take open-source software and compile it for some repository. Most of these people are volunteers and free software enthusiasts.

The repository stores each program as a separate file. All these files have the same format. The format depends on the Linux distribution. Thus, each Linux distribution has its own repository. Examples of the formats are DEB, RPM, ZST, etc. A single file with an application is called a package. A package is a unit for installing software on our system.

The repository stores packages with applications, libraries, and resource files. Besides that, the repository has meta-information about all packages. One or more files store this meta-information. These files are called the package index.

We can install packages on our Unix environment from several repositories at once. It can be useful in some cases. For example, one repository provides new versions of packages, and another offers special builds of them. Depending on our requirements, we can choose the repository for installing each package.