bookmark-save is an interactive autoloaded compiled Lisp function in `bookmark.el'.

It is bound to <menu-bar> <edit> <bookmark> <save>.

(bookmark-save &optional PARG FILE)

Save currently defined bookmarks.
Saves by default in the file defined by the variable
`bookmark-default-file'. With a prefix arg, save it in file FILE
(second argument).

If you are calling this from Lisp, the two arguments are PARG and
FILE, and if you just want it to write to the default file, then
pass no arguments. Or pass in nil and FILE, and it will save in FILE
instead. If you pass in one argument, and it is non-nil, then the
user will be interactively queried for a file to save in.

When you want to load in the bookmarks from a file, use
`bookmark-load', M-x bookmark-load. That function will prompt you
for a file, defaulting to the file defined by variable