Output Redirection(>,>>): It represents the output of a command to some standard output.
who > users
cat users
date >> users # append date in users file
cat user
Input Redirection(<): It redirects the input of a command to a file.
cat filename
cat< filename
Here document(<<): It is used to redirect input into an interactive shell or program.
wc -l << EOF
> This is simple line
> this is also simple line
> EOF
Discard Output
Sometimes you need to execute the command but you don't want the output to be displayed on the screen, in such cases then you can discard the output by redirecting it to /dev/null
Example
whoami > /dev/null
(null is a special type of file which discards the input as soon as it receives)
