“When a user clicks a Like button on your page, a connection is made between your page and the user. Your page will appear in the “Likes and Interests” section of the user’s profile, and you have the ability to publish updates to the user. Your page will show up in same places that Facebook pages show up around the site (e.g. search), and you can target ads to people who like your content.”
Quoted from the official Facebook documentation.