Normally if your using the ubuntu desktop with the gui installed, i would use the ubuntu software centre to install any programs you are looking for. they have a search feature in there to find any program your looking for.

If you want to download an individual .deb package from one of the Ubuntu repositories you can use aptitude.

aptitude download

This will download the .deb but not install it on the system.

Regards,

Jim

First of all define your request

for example you want to install wireshark

then execute:

apt-get install wireshark

if you want, you can upgrade all packages on your system by

1)apt-get update

2)apt-get dist-upgrade

You can find ftp server for debian package after you can get al package

Your question doesn't make any sense.

What in apt-get?

You rarely downloaded packages directly but if you do then use dpkg -i filename.

Otherwise use apt-get update && apt-get upgrade.