AdWords (Google AdWords) is an advertising service by Google for businesses wanting to display ads on Google and its advertising network. The AdWords program enables businesses to set a budget for advertising and only pay when people click the ads. The ad service is largely focused on keywords.
Facebook ads are targeted to users based on their location, demographic, and profile information. After creating an ad, you set a budget and bid for each click or thousand impressions that your ad will receive. Facebook's most important ad targeting options. Users then see your ads in the sidebar on Facebook.com.