The :help command, just like every other built-in commands, is defined in the C code that is compiled into the Vim binary.
You can find in src/ex_cmds.c in the Vim source code.
(Note also that user-defined commands are only allowed to start with an uppercase, precisely to separate them from built-in commands. Also, functions and commands are completely ...
I'm rarely use tabs, but if I make a help window :only, (which is what I have done in the past), and then I switch to the file buffer to try what I learned, the help buffer is gone, and I have to reopen it and re-navigate to the place where I was before to continue reading the help content.
After reading all the answers here, I find that for me :tab is the ...
My personal variation:
command! -nargs=1 -complete=help H help <args> | silent only
This let's you to use :H as you would normally use :help.
only then does the Ctrlw-o combo that others have mentioned.