alias command is used to create our own commands (command shortcuts) so that we don't have to remember/ type repeatedly used/ lengthy commands.

Creating an alias

Following is the syntax for creating an alias

alias name=value

where the name is the new name you want to assign and value is the actual command.
Lets take a realtime usecase so that we can understand easily.
We will type ls -al frequently to list all files in a directory. Lets assign an alias files to the command so that you can simply type files instead typing ls -al. Following command creats the alias with name files for ls- al

alias files='ls -al'

After runnng the about command we can simply type files to list all files & directories, instead typing ls -al

Listing all created aliases

Following command lists all created aliases

alias -p

Example

$ alias -p
alias files='ls -al'

Deleting an alias

We can delete an alias with name using following command

unalias <alians_name>

Deleting all aliases

Following command removes all aliases that are created

unalias -a