A social networking and social media website founded in 2004 by Mark Zuckerberg. Members can create a profile, share information, and connect with people such as friends, family, and colleagues. They can also "Like" posts (i.e. pictures, videos, comments, and articles) and pages (i.e. businesses, places, companies, institutions, brands, products, artists, public figures, entertainment, causes, communities). Users have the ability to send private messages thanks to Facebook Messenger, a free instant messaging service available and directly connected to the site.

Usage comment: Facebook is a registered trademark of Facebook Inc. and must be spelled with a capital letter "F." All other letters are lowercase. The term Facebook can also be used as a verb (i.e. "Facebook me your number" and "I'll Facebook you when I get home").