Neuron 

Also known as a nerve cell or nerve fibers. They are electrically excitable cells in nervous system. Their function is to process and transmit information.

Action potential occurs when  the membrane of a cell’s location is rapidly rising or falling.

Synapse 

Transfers electric activity to cells. The transfer from nerve to nerve.

The axon of the sending neuron does not touch the dendrite from the receiving of the neuron. There is usually a small gap in between them, the synaptic cleft. Neurotransmitters travel across the synapse between axon and the dendrite.

The receiving neuron will determine whether or not to send its own action potential. if it sees if it is excitatory or inhibitory.