Definition
Synapse
A synapse is the junction between the axon terminal of one neuron and a dendrite (or soma) of another. It is the physical site where signals are transmitted between neurons, typically via neurotransmitters crossing a small gap.
Synaptic strength is plastic — it can strengthen or weaken with use. This plasticity is the physical basis of memory and learning. Under the synapses dogma, all long-term information storage in the brain resides in the pattern and strength of synaptic connections.
Connectionism
The synapse is the physical realisation of an association. Where connectionism holds that knowledge is stored in connections, the synapse is that connection — a weighted, modifiable link whose strength encodes what has been learned.