What's difference between escape_string and real_escape_string?

I'm working on dreamviewer. When i'm trying to write basic syntax it usually autocompletes.

As you see it offers 2 variants for "escape&开发者_开发技巧quot;: real_escape_string and escape_string. I wonder, Is there any difference between them?

escape_string is an alias to real_escape_string, so they're identical.