A Neural Impulse is a spike of electrical activity that travels down the length of a neuron (nerve cell). This electrical impulse is triggered by stimulation from other cells and acts to send information throughout the nervous system.
For example, if you touch a hot stove, nerve cells in your fingers will fire, sending impulses through the nerves in your hand, quickly reaching your brain, which will send a signal back down to move your hand away from the heat. Each neural impulse has the same intensity – a cell either fires or it doesn’t – but rate of the firings can differ. Some types of neurons fire faster than others.