How Do You Differentiate Between Zone One and Zone Two?

When I train so I have been training by feeling for many many years now. So like her right it depends what I'm looking for. Some sessions I will look on cadence and some sessions I will monitor the heart rate or the lactate. Zone one to zone two if it was one thing that I would focus more it would be the ability to be breathing all the time on the nose. For me it's where I feel that it's just a easy easy way to to measure it then like zone two It's a very large zone lower zone two it's pretty easy higher zone two is hard.