With aliases and search paths, it can be easy to lose track of what is executed when you enter a command. The type command can tell you which file is executed if you enter a command line that begins with a specific command. For example:

type date

tells you:

date is /bin/date

and the command:

type jobs

tells you:

jobs is a built-in command

You can figure out how the search path works and what effect aliases have.