You don't really
edit
files with Emacs. Instead, Emacs copies the contents of a file into a
temporary buffer and you edit that. The file on disk
doesn't change until you save the buffer. Like
files, Emacs buffers have names. The name of a buffer is usually the
same as the name of the file that you're editing.
There are a few exceptions. Some buffers don't have
associated files—for example, *scratch*
is
just a temporary practice buffer, like a scratchpad; the help
facility displays help messages in a buffer named
*Help*
, which also isn't
connected to a file.