Whats the difference between a press release and an article?

A press release is intended for use by news organizations. Permission to reproduce is given (sometimes with conditions). Traditionally, press releases are mailed to relevant news organizations, and/or released through a press-release agency.

An article is just a generic term for a short exposition on a single subject. While I think it originally referred-to works published in periodicals, it's come to have a wider meaning for any short essay.

And a classified Ad and an Ezine Ad?

A Classified Ad in an advertisement - traditionally published in a newspaper - that is printed under a heading selected from among those made available by the publisher, along with other similar ads.

An Ezine ad is simply an ad published in an Ezine (an electronic publication - email newsletter, online magazine, etc.) Like a "newspaper ad", a "magazine ad", etc.

It makes no sense to ask "is this a Classified Ad or an Ezine Ad?" since clearly you could have a Classified EZine Ad.

For submission of course.

Of course? Did I miss the renaming of this forum to the "Article Submission Mill Forum"?

OK, so THAT's what this is all about!

In that case - they want words, and aren't very picky about them. You got words? Good. Pick the category that fits best. I doubt anybody will notice if it's not quite right.