In this world,all of people go through learning to gain knowledge.Also,someone can be an expertise through continuously learning on the thing that they want to be expert on.From what I have learnt,there are three theories of learning which are behaviorist,cognitiveand constructivist.
BEHAVIORIST
Behaviorist focuses on the observable aspect of learning.
From the action that we observe people can learn something which is known as behaviorist learning theory.

COGNITIVE
Cognitive focuses on processing rather than behavior.
The way we think also included in learning theory which known as cognitivist learning theory.

CONSTRUCTIVIST
Constructivist focuses on construct or build new ideas or concept.
The way we construct something is known as constructivist learning theory.