What is the difference between the terminal button and the axon terminal?

The terminal button, also known as the synaptic knob, is a small structure at the end of an axon that releases neurotransmitters into the synapse during neuronal communication. The axon terminal refers to the broader region at the end of the axon that includes the terminal button and the surrounding structures involved in synaptic transmission. While both terms are often used interchangeably, the axon terminal encompasses the entire end section of the axon, whereas the terminal button specifically refers to the site of neurotransmitter release.