Why am I using async Task and await for DB calls

I'm a noob to .NET CORE and MVC and I'm not understanding why, when accessing the database, My controller methods should use "async Task<IActionResult>..." and when I call the database I'm using "await". I can access the database perfectly fine without doing this, but it seems wrong (according to examples I've read). 

Can someone clarify why I should be doing it this way?