Vi is a very old piece of software. Unless I'm mistaken, it doesn't even have syntax highlighting. Vim is "vi improved" and supports all kinds of stuff, including extensions. Neovim is vim that uses Lua as an extension language, instead of vimscript. That allows for easier creation of powerful extensions.

Nano is a simpler text editor that is not as "powerful" as the vim family. Emacs is a state of mind.

In general, all of these are good tools and get the job done.