Benchmarking is a business practice: you look at a company that does something very well, take its performance as your standard, and measure yourself against it — usually so you can find out where you fall short and copy what works. It is a noun (the -ing form used as a thing), and it is also the -ing form of the verb benchmark. So you can say "benchmarking is expensive" and "we are benchmarking our delivery times against theirs." The word that follows is normally against: you benchmark A against B. Two points on how it is really used. The strict business meaning is comparing yourself with other companies of the same type, and that is what a business textbook will test you on. But in ordinary office English the word has spread — people now use it for any careful comparison against a fixed standard, including comparing this year's team against last year's, or comparing computers and software for speed. In tech, "benchmarking" almost always means speed testing, with no other company involved at all. It is workplace and report vocabulary. Nobody uses it at dinner.