Digg was created at the start of the web 2.0 boom. It was created as a social news site where users submit news and vote the best news articles up the pipeline. How it works is anyone can submit a news article that is found online. Then users browsing the site who find an article interesting can "digg" it. The more diggs and article gets the more popular it becomes and the most popular articles appear on Digg's front page.
Digg is one of the number one places on the Internet to find the latest tech news. Digg is not only for tech news but also has many categories ranging from, World and Business, Sports, to offbeat news. Digg I believe has a heavy lean toward technology news but the other categories have been picking up in popularity everyday.
Other then submitting and digging stories you can also comment on and talk about articles. The comment system at Digg has been of much controversy because a lot of people don't like it. I personally don't have any complaints other then their sometimes are a lot of stupid comments. But going with the websites whole digging concept you can digg comments you like too. But with the comments you can digg them up or down. If a comment gets to many negative diggs it is collapsed by default and you can only read it if you un-collapse it. The comments are also threaded so you can easily tell who replied to who etc.
Recent updates to Digg have created more sections other then just submitting and digging news you like. Digg now offers the submition and digging of, online videos, pictures, and podcasts. Digg is slowly becoming the hub for sharing the most popular things on the web. Digg also has a small social network in the background. Digg always you to friend other Digg users and you can watch what each other digg, submit, and comment on. I personally don't use the friend feature that much on Digg, one social network is enough for me; facebook.
The one great part about Digg is that the developers really do listen to their users. Now maybe they don't respond and do things as fast as some users would like, but they are running quite a big operation these days.They recently just started something they call Town Hall Meetings. These "meetings" will be held quarterly by the Digg founders and they will discuss issues, suggestions, and where Digg is heading. I have not seen one other website on the web that has that much dedication to its users.