What are the characteristics of transformer core?

The commonly used transformer core is generally made of silicon steel sheet. By silicon steel transformer core, because silicon steel itself is a magnetic material with strong magnetic conductivity, it can produce a large magnetic induction intensity in the energized coil, so that the volume of the transformer can be reduced. So why not make the core out of a whole piece of silicon steel, but into sheets? We usually call the power loss in the iron core "iron loss". The iron loss is caused by two reasons, one is "hysteresis loss" and the other is "eddy current loss", and the use of sheet iron core can reduce both kinds of iron loss.