What’s the latest version of macOS you can run on your Mac?

People accuse electronics manufacturers of built-in obsolescence: that hardware is designed to stop working or not be useful after a relatively short period of time. Apple has generally avoided that with Macs, letting many of its models receive OS X and macOS updates for five to seven years after the computer version’s initial release. And some people keep older systems running indefinitely, as I noted in a recent column that started with people’s love of 10.6.8 Snow Leopard, now ov