Computer processors (CPUs) are not brains and are in no way similar to them. I hear it time and time again and I can see why it is such a pervasie non-truth. However, repetition is not an avenue to truth.
There is a direct analogue between Charles Babbage's analytical engine and modern CPUs. There was no way that anyone would assert that Babbage's contraption was a brain but the convenience of invisibility allows many to get away with the illusion. Modern, electronic CPUs accomplish the exact same procedures but do so at the microscopic level using electronic switches instead of gears. Therefore, modern computers are quite literally mechanical machines only that they rely on quantum mechanical rules instead of classical mechanical rules.
So, next time you hear someone saying that the CPU is the 'brain' of the computer politely tell them that it's equivalent to saying that a tractor is the brains of the farm. Makes-no-sense!
Much better is to say that the CPU is the engine of the computer in the same way that your car has an engine under the hood. Believe me: this simple analogy makes a world of a difference.
Just so you know I'm not imaging things: