A computer's CPU is considered the "brain of the computer," being responsible for its major processes, like searching for information, sorting information, making calculations and advanced processes as well as decisions integral to the functioning of the computer. The acronym CPU actually stands for central processing unit and, as such, works behind virtually any task the user is doing on their computer, like writing essays, making photo albums or reading emails. The CPU is made out of a very complex silicon integrated circuit board mounted with tiny, microscopic transistors that can easily number in the billions.
The central processing unit is also sometimes referred to as the microprocessor. It works by getting program instructions from the inputs entered into the computer. These inputs are commonly referred to as RAM. The CPU will interpret the RAM, known as execution, sending back the results, which allows the computer's components to properly carry out the tasks. The CPU performs a task one by one, so the more tasks a CPU can do in a given frame of second, say one second, the more powerful the CPU likely is. For example, if a CPU can perform at 3.9 gigahertz, this means the CPU can calculate 3.9 billion tasks in only one second.