Browsing through page 2 of our "Tags" site, you'll find the templates tag with 72 questions and the documentclass tag with 70 questions. I can't name the difference between the two tags (classes are templates, aren't they?), and looking at the top-scoring questions of each tag, I can't see a distinction, either.
Can someone enlighten me what is the difference between classes and templates? If there is one, is it big enough (and clear enough) to warrant two separate tags? Or would it be preferable to merge these tags into a single tag, say, classes-templates?
documentclass
only makes sense for LaTeX. There is a TeX world outside LaTeX :)