How to Train a Machine to Detect a Cat or Dog?

Machine learning works by extracting some properties, ah, from these images. And we are not conscious of what the machine is doing. Usually it's a black box. It's like the machine is learning and i adjusting this layes in a way that it responds correctly because it gets a penalty. There are kinds of things that each layer might be trained to detect. The only thing is we are not doing t it's very hard to do it consciously.