2) '.' -
3) absolute path - a path to the location of a file or a directory from the root (/) directory
relative path - a path related to the present working directory. example: if I am in /x/y, then /x/y/z is a relative path
4)
5) & makes the shell run in the background. Not using & will make us unable to use the shell while the program is running. we can press Ctrl-z and enter the command 'bg'.
6)