Google, Yahoo, Bing and Social Media offer some form of paid advertising, with Google's Adwords platform being the standard for which the others strive. They typically all offer CPC (Cost Per Click) or CPM (Cost Per 1000 Impressions). The biggest difference between them is usually found in audience and placement.
Audiences on social media are looking for recommendation from friends and followers. Therefore, advertising can be a paid post found within a user's newsfeed. Audiences on search are looking for products and information. Therefore, advertising is usually very specific and product oriented.
All platforms have their strengths and weaknesses. Determine your budget, where your typical customer spends time online and gear your paid advertising to that platform.