If you are reading Info in
Emacs, you can select a new independent Info buffer in a new
Emacs window by typing M-n. The new buffer starts out
as an exact copy of the old one, but you will be able to move
independently between nodes in the two buffers. (In Info mode,
M-n runs the Emacs command
clone-buffer.)
In Emacs Info, you can also produce new Info buffers by giving a numeric prefix argument to the m and g commands. C-u m and C-u g go to a new node in exactly the same way that m and g do, but they do so in a new Info buffer which they select in another window.
Another way to produce new Info buffers in Emacs is to use a
numeric prefix argument for the C-h i command
(info) which switches to the Info buffer with that
number. Thus, C-u 2 C-h i switches to the buffer
‘*info*<2>’, creating it if
necessary.