Both brain and computer are used to store information, process the information and run tasks. It is widely known that brain and computer do have something in common, but in many more ways they are actually more different than they are similar.
Brain and computer combining processes from their components and parts to perform tasks. A computer consists of many parts such as motherboard, disk drives, processor, graphic cards and many more. Each has its own roles and functions. Like a computer, the brain is formed out of parts. The brain has cerebrum, cerebellum, medulla oblongata, thalamus and a lot more.
Use electrical signals
Both transmit information by using electrical signals to each of their parts. Computer components transmit electrical signals through conductors. The computer uses cables, wires and circuits to transmit artificial, stronger electrical signals that travel many times faster than those of the brain. It uses switches that are either on or off (binary). Brain cells signal each other electrochemically and enzymatically. The human brain uses tiny chemical reactions to produce weak electrical signals to communicate with its other parts. Neurons in the brain are either on or off by either firing an action potential or not firing an action potential. However, neurons are more than just on or off because the "excitability" of a neuron is always changing. This is because a neuron is constantly getting information from other cells through synaptic contacts. Information traveling across a synapse does not always result in a action potential. Rather, this information alters the chance that an action potential will be produced by raising or lowering the threshold of the neuron.
Emotions vs Logic
It is impossible for the brain to act without emotions while the computer act only on logic. Researchers already proved that brains act on emotions, that many of our actions are based on our emotional side. We know that computers act completely on logical bits, that are total absolute. All actions performed by computers are based on the instructions in their coding and other factors have no effect on them.
Imagination and Creativity
The computer is faster at doing logical things and computations. It can do creative innovation, but only by using preset algorithms to merge current ideas which only presents a limited range of creativity. The computer can hardly innovate and invent new ideas unlike the brain. The brain is better at interpreting the outside world and coming up with new ideas. The brain is capable of imagination.
Computers have no common sense or real intellect unlike the human brain. Computers can only follow instructions and rules preset by the programmer, they are still not complex enough to understand, analyze and learn about the world like the brain does. Traditional A.I. manages to imitate and resemble human intellect because programmers try to make the computer react like a human brain by defining a set of rules and expectations of behavior for the computer to follow. It is much easier and faster for the brain to learn new things.
The computer can be turned off when we do not want to use it, but the brain works for 24 hours a day. The brain is always changing and being modified. There is no "off" for the brain even when we is sleeping, the brain is still active and working. Different from brain, there is an "off" for a computer. When the power to a computer is turned off, signals are not transmitted.
The brain has 100 billion neurons which form billions of links is many times more complex than, the mere hundreds of millions of transistors and circuit in today's computers. There are thousands of neuroscientists studying the brain. Nevertheless, there is still much more to learn about the brain because of their complexity. There is more we do NOT know about the brain, than what we do know about the brain
Both continue to improve from time to time. But the computers have evolved much faster than the human brain. Computers have been around for only a few decades, yet rapid technological advancements have made computers faster, smaller and more powerful. But the human brain evolves. The brain of modern man is found to be significantly larger than those of millions years ago. A team of scientists uncovered two 1.7 million year old human's skulls, notably smaller with only with 780cc of capacity compared with the 1500cc of modern man's skull capacity which is proof of the human brain's evolution.
The computer can do many complex tasks at the same time (multitasking) that are difficult for the brain and perform complex actions. For example, try counting backwards and multiplying 2 numbers at the same time. However, the brain also does some multitasking using the autonomic nervous system. For example, the brain controls breathing, heart rate and blood pressure at the same time it performs a mental task.