Word has many options to change the format of your text. You can change the font, size, colour, make it bold, italic, etc. If you ever feel like you've made too many changes and want to reset it back to the default plain formatting, Word has a quick button that will do all that for you.
(Instructions for Word 2010) Highlight the text you wish to clear formatting from
On the Home Tab, in the Font Group press the Clear Formatting button (looks like two letter A's with an eraser under it