Hardware

CPU

The CPU is a very important component of a computer.The CPU of the computer completes the "Processing" part of the Input-Process-Output, the CPU also has access to the ROM (Read Only Memory and RAM (Random access memory) the point of having access to these to storage units is for the CPU  to receive instructions on what to perform if an operation is requested. The CPU is the core of every computer system and has two main components: the Control unit and the arithmetic and logic unit. The names are a bit of a giveaway:

• The Control unit uses electrical signals to direct the system to execute the instructions in stored programs.
• The ALU carries out all of the arithmetic and logical operations including addition, subtraction and comparisons (For example: equal to less than).

In order to do this a CPU needs access to two things: the main memory (you would usually call this Random access memory or RAM) where the programs are stored an Cache memory which is usually stored either on the CPU or very close to it so it has easy access to the CPU. The Cache Memory is used to store data waiting to be processed by the CPU. Main memory (or RAM) and cache memory are called primary storage and are part of the computer's processing capabilities. Hard drives and other devices such as flash memory drives, solid-state drives etc. are called secondary storage and these hold data to be kept when the computer.

The Bus System

A System Bus  is a single that connects the major components of a computer system. The technique was developed to reduce costs and improve modularity. it was mainly used during the early 70s and late 60s.