need some help clarifying with Isometric and Orthographic and errors doesn't show up in VS but it does in Unity

hey, I have 2 different questions that I need help with

I need some help with clearing up the differences between Isometric and Orthographic, I thought Orthographic only shows one face of something whilst Isometric is seeing things in a 3D dimension but, when I watched a persons video on Unity I saw that the person referred the ISO view as an Orthographic, which made really confused.

2nd question. When I am coding my Unity Scripts in my Visual Studio, any error which I was supposed to get, that aren't related to forgetting to close of my "" or not putting an ; at the end of a statement, do not show up at all, as well as the different colour for an unused variable. However, when I copy paste it into a new project which isn't related to Unity at all, the unused variable colour and errors show up. Can I fix this?