Counters are widgets that, well obviously, count. They count the number of hits your website has, and you - and your viewers - will be able to see how popular and how many hits you recieve.
A few web analysis tools include:
An RSS Feed is a web feed used to inform subscribers about frequently updated works; it allows people to subscribe to a feed and it will automatically update them when the site is edited and new information is added.
Google reader is a simple way to subscribe to RSS feeds and is found in Gmail.