Neurons communication within itself is known as electrical. Neurons have intracellular signaling which is another way to say communication within the cell. Communication between cells is another way for saying intercellular signaling. Action potentials are needed when sending signals that are electrical. Neurotransmission is communication between neurons.
Conduction
Action potentials are needed to start conduction. Action Potentials are electrical signals. These electrical signals move along a neuronal membrane that has ions. Ions play an important role in this because they move freely around the membrane and control what the entire charge of the neuron is. Depolarized is when the neuron is more postive and polarized is when it is at a steady pace of -70 millivolts. A threshold is when the neuron has depolarization that is greatly over the amount needed. This is when an electrical charge is made. After this action potential is reached the signal goes to the axon terminals where the conduction ends.
Neurotransmitters
This is communication between two neurons. It can be chemical or electrical. Neurons receive information by the input they get in and then send information as an output. This process is done through electrical synapses. In electrical neurotransmission the communication of the neurons is done by a synapse that is electrical. These synapses have gap junctions that connect to two neurons where they act as one together. In chemical neurotransmission the communication of the neurons is done by a synapse that is chemical. The gap here is called the synaptic cleft where a barrier is made so that the signal can travel along it. One neuron is transferred to another. The neurotransmitter is like a chemical messenger.

Consortium on Cognitive Science Instruction 2008. Neurons, Synapses, Action Potentials, and Neurotransmission. 11 06, 2008, from
http://www.mind.ilstu.edu/curriculum/neurons_intro/neurons_intro.php