What is the difference between WikiProjects and portals?

• WikiProjects are groups of editors who team up to collaborate on developing and maintaining articles or other features or aspects of Wikipedia. There is a Portals WikiProject, for example. WikiProjects are linked to from article talk pages with WikiProject banners like {{WikiProject Politics}} for example, but not from within articles.

• Portals are mainly for readers, providing an alternative doorway into a subject, and can be linked to from articles using the {{Portal}} template in an article's See also section. There may or may not be a WikiProject and a portal on the same subject.

By the way...the WikiProject Portals is currently redesigning and revamping the entire portals system, and could use all the help it can get. New participants are welcome.