Here lie posts about updates. This is, usually, new information about the site or about an already existing body of knowledge/material. Sometimes things go out of date, or a technology’s specifications change. This requires an instructor to go back and revise. They renew their lesson plans so that they are accurate and relevant.
That’s what these articles point out. They can also serve as errata (though in a different way than books since you can easily correct online text) and other materials for articles. Some articles deal with ongoing projects, and updates to those projects are also found here, so keep your eyes peeled.