what does "sudo apt-get install aptitude" do?

I am completely new to linux and hence Ubuntu. Though i have been using the Ubuntu OS on my system for a while, it is for the first time I am trying to learn the nuances and hence starting with the documentation.

I am wondering , if we use apt-get command to install packages, what does apt-get install aptitude do ?

apt-get install PACKAGE_NAME

Is the command used to install any package you know the name for, like aptitude.
sudo is used to earn root access and be able to install and remove software. sudo is always required if you do system wide changes like installing, removing, updating and upgrading packages.

apt-get

Is the command used to manage any software and software sources. install is an extra command that tells the computer that you want to install software with the package name as follows. It will then check the software sources for a download link with the same name and then download and install the latest version (or specified version).

update

will update the sofware sources with new versions of the software listed (not installing anything)

upgrade

upgrades the software if new versions are available in the software sources.

remove

removes the package name specified after (like install).

there are more useful commands, but these are necessary for getting started with managing software from the terminal.

Aptitude
After more research on aptitude i found out that it's already installed. So installing aptitude wouldn't resolve in anything besides errors in the conosle. Start aptitude by:

sudo aptitude

The aptitude package is a GUI version of the apt-get command, it hasn't got the full set of features as apt-get but you have the basics like, remove, update, upgrade, install, etc. More information about aptitude and it features can be found here.

Also search in the software center if you want o use a GUI to find and install/uninstall applications.

Useful sources:

• Installing software - Ubuntu wiki

• apt-get/HowTo - Ubuntu wiki

simple , it will install a package named as aptitude.

the syntax of installing packages is sudo apt-get install <pkg_name>

for more information : wiki-Ubuntu