How does apt-get work?

It is not wrong to browse the help.ubuntu.com first
We are all willing to help but sometimes you will find great answers to frequently asked questions there:
for apt-get have a look here
https://help.ubuntu.com/community/Ap...ct=AptGetHowto

if you have downloaded a .deb, all you need to do to install it is double-click on it then press "install"

if have packs on a flash that i want to install
do i just do the
sudo apt-get pack.deb

and the comp will find the pack on my flash and dload

Also if you ever want to know more about a program or command try looking at it's man page, can be kinda cryptic at times but does provide insight

simple, launch a terminal (applications > accessories > terminal)

then type

to install something
to uninstall something
to upgrade everything

Thats a very simple version of how to use it, there are more complicated things you don't need to worry about right now.

You can also go Applications > add/remove and it's very simple, you type in what you're looking for, check or uncheck it, and click apply

hope this helps

apt-get is the method that is used to tell the system to install (and download from the repo if needed) software. It can also work in reverse to remove a program

ie. sudo apt-get install build-essential

tells the system to download and install the files associated with build-essential

sudo apt-get remove amsn

will tell the system to remove amsn from the computer