Below is a brief overview on using the bash Shell. The history command provides a shortcut for users in that previous commands can be reintroduced and possibly modified. You can access these previous commands using the UP and DOWN arrows. The history file is maintained across login sessions. In the simplest form, the arrow, backspace, and delete keys may be used to edit these lines.
Aliases provide a means of shortening the name of a command or sequence of commands.
When you type an alias on the command line, the shell replaces it with the command sequence to which it refers. Aliases effectively allow you to abbreviate commands and to alter the meaning of existing commands from your point of view. Users can return to the previous directory without typing its whole pathname. Aliases are usually performed only on the first word of a command. If the command name matches an alias, the command is replaced by the text of the alias.