Chapter 1: Introduction to Computers and Programming
Computers are everywhere! They're in our smart phones, office, home, navigation systems, game consoles, tablets - and they're even in our cars and other devices!
Computers can do anything they are programmed to do! A program is a set of instructions that a computer follows to perform a task. Programs are commonly referred to as software.
A computer system consists of the CPU, main memory, Input and Output devices, and secondary storage devices
Hardware is the physical part of the computer that you can touch. It includes all physical devices, or components, that the computer is made of; Central Processing Unit (CPU), main memory (RAM), secondary storage devices, input devices and output devices.
The CPU (central processing unit) is the brain of the computer. It is what actually runs programs. It is also known as the processor. Today's CPUs are tiny chips known as microprocessors.
An Intel Core i7 processor is shown to the right.
Main memory is the computer's work area. When we load a program, it loads in to the main memory, also known as random access memory (RAM). RAM is very fast memory, but it is volatile, which means that when the power is off (or if it blinks), everything in RAM is lost.
Secondary storage is a type of memory that can store data even when the power is off. Programs are normally stored in secondary memory and loaded in to main memory when needed. The hard disk, or disk drive, is the most common type of secondary storage device today. However, solid state drives, which are much faster at accessing data, are becoming less expensive, and are increasingly popular. A solid state drive has no moving parts like a hard disk.
Other secondary storage devices include USB drives (flash memory), compact disks (CDs), and digital versatile disks (DVDs). Cloud storage has become a popular way to store data. When we store data in the cloud, we're storing it on a remote server via the Internet.
Input devices are devices that collect data and send it to the computer. Input is any data the computer collects from people or other devices. Common input devices include keyboard, mouse, touchscreen, scanner, microphone, and digital camera.
Output devices are devices that the accept data form the computer. Examples include printer, speaker, display.