One way to install applications on a linux machine is using the “sudo apt-get install application name” command. But in case you have a lot of applications already downloaded from the internet in the form of .deb packages then this is how you install them.
Head on to the place where you have got a particular .deb package. In case you have downloaded a package and saved it in your downloads folder, you would type…
This will change the current directory to Downloads.You can typelsto find out if the package you are looking for is present in the folder. (ls command lists the files present in the directory you are currently in.
Once that is done. Type
dpkg -i packagename.deb
Where package name is the name of the package you are going to install. Foe example if you have a .deb file for opera browser in that folder. You can type the first three or four characters of the package name and then press TAB key, the rest will be filled out automatically. You can use this tip almost anywhere in the terminal while changing folders using thecdcommand also. Else you can choose to type the whole thing also, which I suggest is not the way to go if you wanna do things faster.
dpkg is a Debian Package Management System. You can use it to install, remove or get info about packages. “-i” in the command above corresponds to install. Similarly “-r” can be used to remove a package.
This will install the package. Wait for it to finish installing till you get the prompt.
Hope i was clear… Post in your doubts…