Laura Shoe has written an article clarifying the names and what they apply to. It's especially important to know which version of the software you are using. Doing any kind of search on the internet now means you need to be a detective to ensure that the results actually apply to your version of the application.
In "Lightroom Applications Names Change Again – Why You Need to Pay Close Attention", Laura has made a graphic illustrating the name and product changes that really helps clarify what's going on. And she provides suggestions on how to tell which version of Lightroom you're using.
I highly recommend this article so you are clear on which products are which.