A business or an industry is capital-intensive when it needs a great deal of money tied up in machines, buildings, tools, or land, and relatively few workers to run them. Making computer chips, flying passenger planes, and building power plants are capital-intensive: the kit costs a fortune before anyone is paid a wage. You hear the phrase in economics, in news about factories, and in talk about why some industries are hard to start. You cannot open a chip plant with a small loan.

Capital here means money and equipment, not a capital city and not a capital letter. The usual pair is labour-intensive (American spelling: labor-intensive), where you need many hands and less heavy machinery — picking fruit, a busy restaurant kitchen, some kinds of care work. Though actually, many real companies sit in the middle: some expensive machines, still quite a few people. So the label is a leaning, not a clean box. It does not mean the work feels emotionally intense, and it does not mean the owners are intense people.