I learned a few new commands that I haven’t used before:
To find a list of possible locations for a given application (in this case I choose “apt” which isn’t really a binary by itself, but rather a directory name used by “apt-get”.
$ whereis apt
apt: /etc/apt /usr/lib/apt /usr/share/apt /usr/share/man/man8/apt.8.gz
$ whereis apt-get
apt-get: /usr/bin/apt-get /usr/X11R6/bin/apt-get /usr/bin/X11/apt-get /usr/share/man/man8/apt-get.8.gz
Very cool for finding things quickly. If you didn't catch what the output is, it is a simple space-delimited list of matches following the application name.