Classical conditioning and operant conditioning are two major types of conditioning that are used to modify behavioral patterns.

Classical conditioning involves learning by association where a neutral stimulus is repeatedly paired with an unconditioned stimulus until the neutral stimulus becomes a conditioned stimulus that triggers a conditioned response. This type of conditioning was first discovered by Ivan Pavlov and is often used to explain how animals learn to respond to certain stimuli.

Operant conditioning, on the other hand, involves learning from the consequences of behavior. A behavior is more likely to occur if it is reinforced by a positive consequence or if it results in the removal of a negative consequence. Similarly, a behavior is less likely to occur if it is followed by a punishment or if it leads to the addition of a negative consequence. This type of conditioning was first discovered by B.F. Skinner and is often used to explain how humans and animals learn to perform certain behaviors based on the outcomes they experience.

In summary, classical conditioning involves learning by association while operant conditioning involves learning from the consequences of behavior.