I think, you are talking about what I'd call the "testing environment". For me, development environment is made of the editor, tools that work on my source cod

I think, you are talking about what I'd call the "testing environment". For me, development environment is made of the editor, tools that work on my source code s.a. compilers, linters, maybe language server etc. and things that help me with administrative tasks related to programming (eg. bug tracker, version control, communication channels). In my practice, it's very uncommon to be able to run even a small portion of the project I'm working on on my personal computer. There's usually no way for me to even attempt to set up anything resembling the system I'm building on my computer. Which is unfortunate, and I'd love to be able to, but it's just physically impossible. I don't know how typical my case is. I'd assume that programmers working on desktop applications or phone / Web stuff are more likely to be able to fit their entire product or at least a significant portion of it on their own computer. In which case they could think about their testing environment as being part of their development environment. Still, I'd not call it that... I mean, conceptually, it's for testing, so it's a testing environment. You don't need it to do development, it's just coincidental that you have both in close proximity.