Page breaks can be inserted to force the content to begin at the top of a new page. For example, a page break should be used at the end of the body to ensure the references/bibliography starts at the top of a new page. Page breaks maintain consistent formatting between the two pages (meaning: page numbers, margins, page orientation, etc.).
Section Breaks allow for formatting to be changed between pages or columns. This can be useful to change the page numbering type (between Roman and Arabic numerals in Word, for example) or to change the page orientation to create a landscape page.
Column breaks allow you to split the text or other items across a page to allow more readability in the document. This should be used sparingly but can be a useful tool when used correctly.
To access breaks in Google Docs, locate the break menu under "insert":
To locate breaks in Word, find the layout tab on the ribbon:
