Learning Terminology and Foundations
You might want to know a few terms before we continue. These are words used to describe how the software gets installed on your machine as well as how the system works.
- APT: Advanced Package Tool, or APT, describes the entire system of online repositories and the parts that download them and install them. This is not highly visible when using graphic interface–based systems like Ubuntu Software Center but very clear when using command-line tools like apt-get, which is described in greater depth in Chapter 8. Whether you use a graphical interface or the command line to deal with Ubuntu software packages, APT is at work.
- Repositories or software channels: In the Ubuntu world, these giant online warehouses of software are divided between official Ubuntu repositories and unofficial ones.
- Packages: Applications are stored in packages that not only describe the program you want to install but also tell your package manager what the program needs to run and how to safely install and uninstall it. This makes the process of dealing with software dependencies smooth and easy for end users.
- Dependencies: Dependencies comprise the software that is needed as a foundation for other software to run. For example, APT is needed for Ubuntu Software Center to run because APT takes care of many of the details behind the scenes.