What is inside a Computer ?

The five main sections of a Computer are input. memory, arithmetic and logic, control and output . Here is a brief description of each .
Input:  This  consists of all the  circuits needed to get programs and data in to the computer . In some computers the input section includes a typewriter keyboard that convert letter and numbers into strings of binary data .
Memory: This stores the program and data before the  computer run begins . It also can store partial solutions during a computer run, similar to the way we use a scratchpad while working out a problem .
Control: This is the computer's center of gravity, analogous to the conscious part of the mind . The control section directs the operation of all other sections . Like the conductor of an orchestra , it tells the other sections what to do and when to do it.  
Arithmetic and Logic: This is the number-crunching to the machine .It can also make logical decisions . With  control telling it what to do and with memory feeding it data, the arithmetic-logic and unit (ALU) grinds out answers to number and logic problems.
Output: This passes answers and other processed data to the outside world. The output section usuall includes a video display to allow the user to see the processed data.