Until now we have discussed how to install Ubuntu, concepts around files, keyboard shortcuts to navigate easily and various ways to customize Ubuntu with Gnome shell. Today I am going to discuss how to install applications in Linux along with the various ways to do them, and will end with a special note that would explain how “running” applications in Ubuntu is fundamentally different than Windows.
You must be used to installing softwares in Windows by downloading .EXE files or .MSI installers. You open these files and click Next -> Next and viola. Installing applications in Ubuntu is a bit different and safer than Windows in some cases. But before we get into the steps its important to understand the concept of Packages in Ubuntu.
What is a Package?
A package can be considered a collection of files bundled into a single file. Package contains among other things, the installation script which tells where the files will be copied and what settings needs to be changed once the package is installed.
In essence, the output of a package is equivalent to .exe or .msi installers, that is they install a software on the OS. There are many ways to install a package on Linux. You can install a package using Package manager which itself are categorized in Low-Level and High-Level package managers. You can also download packages over the Internet and use it to install it on the system (more on this later in this article).
Low level package managers are dpkg (for Debian based Linux like Ubuntu) and rpm (for SUSE and Fedora). While high level package managers are apt-get (for Debian), zypper (for SUSE) and yum (for Fedora).
Packages can depend on other package to be installed first. Say if you want to install some software which was written in PHP, you may need to install the PHP package first. This concept is called dependency and is usually taken care of itself if you are using a high level package managers.
Advanced Packaging Tool (APT)
The underlying package manager in Ubuntu (or any Debian based Linux) is APT. You can use the command apt to install or remove packages on your system. APT is also used in background in GUI based package managers like Ubuntu Software Center and synaptic.
EDX have a pdf which lists some basic commands to using package managers. Download it here.