What's difference of apt-get and aptitude?

aptitude is supposed to be a user level program whereas apt-get is supposed to be used by higher level programs. It just turns out apt-get is easy to use so people just use it instead of the higher level managers like aptitude and synaptic.

aptitude is more user-friendly because it adds a layer of abstraction away from apt-get, apt-cache etc..; apt-get is more user-friendly than dpkg for the same reason. It's really down to the user's knowledge and what works best for them. aptitude and apt-get use the same repositories. Let it be clear that aptitude does not itself run apt-get apt-cache etc.. I merely mean to point out that aptitude is a higher level package manager.

The levels of abstraction:

• aptitude - High level of abstraction
• apt-get, apt-cache, etc.
• dpkg - Low level of abstraction

apt-get and aptitude are both front ends to dpkg. Use one or the other but be consistent. aptitude is newer and is suppose to be easier to use. It also unifies some of the apt-* functions. You can use aptitude to search and install while with apt-* you need apt-get and apt-cache for installation and searching respectively.

Source: Superuser.com

Few other links you might like to read.

1. Aptitude vs. apt-get: Which is the recommended (aka the “right”) tool to use?
2. Is aptitude still considered superior to apt-get?