We use “keyword” quite a lot in our software products and also in our documentation.
Keyword is a word which here and everywhere where we write means:
“keyword or keyphrase (key phrase). it can be made up of one word or ten words. Length doesn’t really matter for the purpose of this definition”
There you have it.
Some people think a keyword is only something like “wordpress”. Whereas something like “wordpress premium themes” is a key phrase.
We don’t care about such lengthy and complicated definitions. We’re calling all of them keywords, in order to be able to provide as much clarity as possible.
If anybody ever asks you about this, just refer them to this page.
At the Squirrly company we also think of topics in terms of keywords.
“WordPress Premium Themes” is a topic and a keyword at the same time. Therefore, we usually just use either “topic” or “keyword” in such cases, so that we do not repeat ourselves.
The topic of a page, of an article, of a presentation, or of a video could very well be the keyword that you’d optimize that content type for.