“Content management system”.
This can mean a lot of things. But in (over)-simplified language, it gives you a way of modifying web pages from a browser without having to fire up RapidWeaver.
This is particularly useful if you want to make frequent changes from the road, or if you have other people who need to be able to make updates.
Two examples of where you might want one:
- You are maintaining a blog and want to be able to update it without republishing your site, or want to allow other people to contribute to the blog
- You run a store and want to easily add/remove products, change prices, etc., without having to republish your site