Ls

ls is the basic "LiSt me the contents" command used in a unix shell. It operates on the current directory by default, and displays a list of all files, directories, pipes, sockets, symlinks, and devices.

There are many, many options to ls, and they can vary greatly from system to system. Check the local man pages for details.

ls -lart

is a popular usage with arguments. A long listing which shows .files, reversed by time. You can alternatively shell:alias this if you use it a lot.