where do installed programs disappear to?

[JoeYsUn]

Sometimes i install programs and they just disappear... i'm told they're installed but they're invisible to me... How can i find them? is there something like "windowsexplorer" where i can find all the installed stuff?
thanks

[welwitschia]

Can you describe in more detail what happened?

[oldos2er]

Which programs? If they're CLI apps, they won't have a menu entry.

You can see where each file in a package is installed with
dpkg -L <package name>