How to change the buffer name in emacs to any given string? Useful if one has many shell buffers for various specific tasks and is merely seeing their order of creation.
In this particular case, C-u M-x shell helps by giving each shell buffer a unique name, using a counter that increments every time.
If you want to give them more meaningful names, M-x rename-buffer RET foo RET will do the deed.
C-h f rename TABorapropos buffer rename.