Max is a visual programming environment, think of it like a programming language like Python but it's rather visual. It has whats called "objects", that u can chain together to your liking, creating algorhithms. For example there is a [saw~] object, which will generate you a sawtooth wave. If u plug in a [numberbox] to it which just allows u to output numbers, and say that numberbox is outputting 440 then u have a sawtooth wave playing on 440 hertz. There is a [metro] which is a metronome, that you can turn on, also give it some time in miliseconds, for example [metro 500] will give you a bang every 500 milliseconds (equivalent to 120bpm). There are thousands of these objects, though the core objects are around a few hundred. Chain these however you wish and you create "patches". There are also a bunch of visual objects like dials, sliders etc. Basically like a gigantic lego collection but it is up to the user what you will create out of it. The user range is pretty wide, from doing live visuals, audio reactive stuff, to making and prototyping instruments (some of the Elektron stuff was protod in Max), building effects, Max4Live devices etc. Ae uses Max in a pretty unique way, they basically create a bunch of patches in the studio that are spitting out different algorhithms and they swap those patches live, allowing them to change controls in real time, since its all generated live, there are no audio files and such in there.