Final answer:
The gap between neurons, where neurotransmitters are released from the axon terminal and travel to another cell, is called a synapse.
Step-by-step explanation:
The gap between neurons is called a synapse. This is the location where the axon terminal of one neuron comes close to another cell but does not physically touch it. Instead, neurotransmitters released from the axon terminal cross the narrow space known as the synaptic cleft, which is approximately 20 nm wide. Once neurotransmitters reach the other side, they bind to receptors on the other cell, which may be another neuron or a different type of cell like a muscle cell.