Q: How to edit file content using zsh terminal?

I created an empty directory on zsh and added a file called hello.rb by doing the following:

echo 'Hello, world.' >hello.rb

If I want to make changes in this file using the terminal what's the proper way of doing it without opening the file itself using let's say TextEditor?

I want to be able to make changes in the file hello.rb strictly by using my zsh terminal, is this at all possible?