Hard return: Pressing the Enter key in Word ends a paragraph. It’s officially known as typing a hard return. Yes, it’s a return even though the key is known as Enter on a PC. The problem with the hard return is that it adds a bit of “air” after a paragraph (a double spaced line). That’s a good thing; you should have air around paragraphs in a document.

Soft return: Those times when you don’t want air, when you need to put lines of text close together, you use a soft return(a single space line). The soft return, or line break, is used primarily in titles and headings; when you have a long title and need to split it up between two lines, you press Shift+Enter to insert the soft return.