The best way to understand what is direct deposit is to think of how you receive your salary in your bank account. This electronic transfer of funds that gives you easy access to money without a paper cheque is the exact direct deposit meaning.
A direct deposit helps your account get credited without requiring you to wait or take any action on your own. You usually get your pay from your employer or even your tax refund via a direct deposit. Today, you also get the loan amount straight into your bank via direct deposit, which is very convenient.