In bash scripting `elif` is used for multiple conditions check. if the first condition is false, next condition is checked and so on.
it differs from `if` and `else` in a following way:
In `if` and `else` , if the condition is true then if block is executed and if it is false then else block is executed but to check multiple conditions before else block we use `elif`.
Among them only one statement is true and corresponding block will be executed.
