The following is a (non-exhaustive) list of computer science symbols/terms you may see during your career.
. (Unix Directory)
In Unix filesystems, the . symbol represents the current working directory.
.. (Unix Directory)
In Unix filesystems, the .. symbol represents the parent directory to the current working directory
. (Unix file)
In Unix filesystems, files beginning with a . symbol are considered hidden, and do not show up in standard file listings.
Unix command to change the current working directory.
Unix command to list the contents of the current directory
Unix command to print the working directory.