An item that toi can 'fan' can be several things here on fanpop: video's, images, articles and links. If toi see an item toi like, and toi would like to express that, toi can become a 'fan' of that particular item (similar to the 'like' button on Facebook).
When toi click the green button that says: 'fan of it?', toi become a fan of that item. Becoming a fan of an item doesn't have big consequences for you, it just means toi like this item. It can help other users to find good quality content (if a lot of users are fan of an item, it's probably good quality).
If (for some reason) toi would like to 'unfan' a certain item, do the following: Go to your profil page. Click on 'Favorites'. Click on 'Content I'm a fan Of'. Find the item toi would like to stop being a fan of and simple click on the little red cross.
