If you haven't figured out exactly what Pinterest is -- or how to use it -- it's about time you wise up. The platform recently became one of the top five social networks on the Web in terms of weekly visits.

For a quick rundown of all the things you need to know about Pinterest, we've gathered the most pertinent information about the hottest new social-media platform on the Web.

1. What makes Pinterest unique?

Pinterest allows users to pin a link to any Web site on the Internet. Each link is represented with a large photo. Users can comment below pinned photos or click through to the Web site it was originally posted on.

Items that are pinned are organized into groups known as boards. A board is essentially a checkerboard of photos that have been pinned.

The photocentric design of Pinterest makes it different than any other popular social network. Many people use Pinterest to bookmark recipes, wardrobe ideas, wedding ideas, and workout plans. That's quickly changing, however, because more people are joining.

2. Pinterest is a members-only site.

For now, Pinterest is only available to those that are invited. There is a very good chance that one or more of your Facebook or Twitter friends are already on the network, so it may just take a simple request via another social network to get an invite.

There are currently no workarounds to the invite-only nature of Pinterest. If you're desperate, visit the Pinterest Web site and request an invitation.

3. Celebrities and brands are joining.

Several high-profile techies and large brands have joined Pinterest. Some examples include Reddit founder Alexis Ohanian, television cook Paula Deen, supermarket chain Whole Foods, handmade online commerce Web site Etsy, and General Electric.

4. Pinterest is popular among women.

Pinterest has more than 10.4 million registered users, according to Inside Network's AppData tracking service -- and about 97 percent are female.

5. Pinterest is generating lots of buzz and even more money.

Pinterest is attracting more than 11 million visitors a month according to Hitwise, and investors are taking note. The company's valuation has grown five times. It's currently valued at $200 million.