make>>make.fail 2>&1

tells it make and then to send (>) stderr (2) to stdout (1) and also to send stdout that way also (&1). finally all of that gets sent to a file named make.fail (>>). Isn't '>>' actually 'append' whereas '>' would work just as well so long as the file didn't already exist? If the file did exist would I get an error or would the file be overwritten?