In the concept of psychology USR,CS and CR is Expresses what?

In the concept of psychology, USR stands for Unconditioned Stimulus Response, CS stands for Conditioned Stimulus, and CR stands for Conditioned Response. These terms are used in classical conditioning to describe the relationship between stimuli and responses in the learning process.

Unconditioned Stimulus (US): A stimulus that naturally and automatically elicits a specific response.
Unconditioned Response (UR): The natural, unlearned response that is automatically elicited by the unconditioned stimulus.
Conditioned Stimulus (CS): A previously neutral stimulus that, after being paired with the unconditioned stimulus, eventually elicits a conditioned response.
Conditioned Response (CR): A learned response that is elicited by the conditioned stimulus.