Photo of the Month: Jan 2019 - Plant of the Month: Feb 2019
Watched threads are the threads you have subscribed to. You'll see members make a short one word post "subd" that's because posting in a thread subscribes you to it. You can also click the subscribe button on the first page of a thread. Keeps them organized so you can follow along. A lot of folks don't realize you only get a notification for the first post after yours in a thread, if you don't go back after every new post you don't a new notification. But using your watched threads let's you keep an eye on the threads your interested in.