One of my favorite features of Vim is that it completely decouples tabs/windows from files/buffers. In mostly all IDEs I'm aware of, you open a file, and you get a tab to go along with it. In Vim, I have one instance (of Vim) running, maybe just one window if I feel like it, and potentially hundreds of files open, maybe some edited but not saved yet. And all I do it switch in and out which file/buffer I want to view in my one window. (more typically 2-4 panes/windows, and yay BufExplorer for making that easy)