VSTS or VSTE? whats the diff?

sometimes i hear people call it VSTE, and sometimes VSTS (well its the edition for testers im talking about). but actually they were talking about the same things. and i know this two terms are just the main branch of other stuff like, dev edition, test edition, TFS.. etc..

so is it accurate to say that VSTE is its old name? cuz i dont see any VSTE in MSDN, just VSTS