I've been taught that "assembly" is what you write in your files, to have your "assembler" convert it into binary code.
But I see these two terms mixed and matched in various works. I've even heard that you write "assembler", after which an "assemblator" makes it executable.
What's the right words to use?
Actually, the language is called "Assembly Language", and the tool to convert it to machine code is the "Assembler".
More info on Wikipedia: http://en.wikipedia.org/wiki/Assembly_language