Is there a place (website) to view all packages that can be installed with apt-get, or rather search for one based of some criteria such as key-phrase, similar to what you can do for npm? Where are these packages that are being installed being stored? How does someone add a package that can be installed with apt-get?
apt seems like a mystery tool that the only reason people know what packages that can be installed install is because of a forum or Stack Overflow post told them too, where's the master list if there is one?
man apt
, and there should be a complete user guide in/usr/share/doc/apt/
if you install theapt-doc
package. BTW, to search for packages tryapt-cache search
. and, of course, see Package Management on the debian wiki.