Computer Basics• A computer is one of the most brilliant inventions of mankind

and thanks to the computer we are able to increase the amount of work we do each day, access vast amounts of information, participate in our global community, and stay instantly connected.

• Computers are machines that perform tasks or calculations according to a set of instructions, they allow us to efficiently store and process massive amounts of data. The first fully electronic computers, introduced in the 1940s, were huge machines that required teams of people to operate. Compared to those early machines, today's computers are amazing. Not only are they thousands of times faster, they can fit on your desk, in your lap, or even in your pocket.

Turning the Computer On

• When you turn on the power to a computer, the first program that runs is usually a set of instructions kept in the computer's read only memory (ROM). This code examines the system hardware to make sure everything is functioning properly. When your computer is powered on it runs a power-on self test (POST). The POST checks the CPU, memory, and input/output systems for errors. Once the POST has successfully completed, the software loaded in read only memory (ROM), will begin to access the computer's disk drives.

Turning the Computer On (cont.)• In most computers, when the computer activates the

hard drive on startup, it finds the first piece of the operating system (OS), called the bootstrap loader. Did You Know: When you turn on a computer it is commonly referred to as "booting up", this term is short for bootstrap and used to describe the process taken by the computer when it loads the OS and prepares the system for use.

• After the operating system has loaded the user takes back the control and the information processing cycle begins.

OS & Software• An operating system or OS, is a software program that

enables the computer hardware to communicate and operate with the computer software. Without a computer operating system, a computer would be nothing more than a useless box of parts. As computers have progressed so have the functionality of the operating system.

• The first computers were all command driven, if a user wanted to launch a program or print a document they would have to know the correct command, nowadays operating systems are driven by graphics. GUI - Short for Graphical User Interface, a GUI Operating System contains graphics and icons that a user can click to perform a function or execute a program.

Types Operating Systems

• Windows 7 , 8 , and 10• Windows Vista• Windows XP• Mac OS• Mac OSX Panther• Unix• Linux

What is Software?• Software is the term used for different types of

programs used on a computer. It is often divided into application software (user driven) and system software (which includes operating systems and any program that supports application software).

• Software comes on CDs or DVDs. Today, much of the software is downloaded over the Internet. Software can be purchased or acquired as shareware (usually intended for sale after a trial period), freeware (free software but with copyright restrictions), and public domain software (free with no restrictions).

What is Spyware?• Spyware is a type of malicious software (malware) that is

installed on a computer and collects information about users without their knowledge.

• Spyware programs can collect various types of personal information including, Internet surfing habits and sites that have been visited, it can also interfere with a users control of the computer in other ways, such as installing additional software and redirecting websites.

• Spyware is known to change computer settings, resulting in slow connection speeds, different home pages, and/or loss of Internet, or functionality of other programs. Although programs exist to detect and rid computers of spyware they are not always effective.

Information Processing Cycle

• What is the information processing cycle? The sequence of events in processing information, which includes (1) input, (2) processing, (3) storage and (4) output.

These processes work together and repeat over and over.

1) Input—entering data into the computer. 2) Processing—performing operations on the data.3) Storage—saving data, programs, or output for future use.4) Output—presenting the results.

Input Devices

Input is the collection of raw data and putting it into an information processing system or computer. Input devices can be hardware devices, software, or user driven.

Examples of Hardware Input Devices: • keyboard• mouse• scanner• bar code reader• joystick• digital data tablet• microphone

Input Devices (cont.)

Examples of Software or User Input:• Programs are instructions that direct the computer.• Commands are key words that the user inputs to

perform a task. Examples include, choosing Open on the File menu or using shortcut key, they may also be chosen by clicking on a icon or button.

• User responded to the questions given by computers, such as choosing OK, CANCEL, YES, or NO or by typing in text, for example a file name.

Processing & Storage

Processing• The system unit is the core of a computer system and the main

processing center. Usually it's a rectangular box that holds many electronic components that process information. The most important part of these components is the Central Processing Unit (CPU) also called the processor. The CPU is the brain of your computer it is the key component in interpreting computer program instructions and processes data. The next most critical element of a processing is RAM, often referred to as "primary storage" or "main memory". Random Access Memory (RAM) temporarily stores information that the CPU uses while the computer is on and is erased when the computer is turned off.

Processing & Storage(cont.)

Storage• Computers usually have one or more disk drives,

commonly referred to as a hard drive—devices that store information. The disk preserves the information even when your computer is turned off. All computers have a hard disk drive that can hold massive amounts of information; they usually serve as your computer's primary means of storage, holding almost all of your programs and files. The hard disk drive is normally located inside the system unit.

Output Devices

• Output is the presentation of any data exiting a computer system. Types of output include visual, printed, or audio.

Types of output devices include: • Monitor• Printer• Projector• Speakers

Types of Computers

• Computers come in all sorts of shapes and sizes and serve a variety of purposes. Not too many years ago, computers were the size of a large room and consumed huge amounts of power. However, with the advances in technology, computers have shrunk to the size of a watch. Depending on the processing powers and sizes of computers, they have been classified under various types.

Different types of Computers Supercomputers: Highly calculation-intensive tasks can be effectively performed by means of supercomputers. Quantum physics, mechanics, weather forecasting, molecular theory are best studied by means of supercomputers. Mainframe Computers: Large organizations use mainframes for highly critical applications. Most of the mainframe computers have the capacity to host multiple operating systems and operate as a number of virtual machines and can thus substitute for several small servers.

Different types of Computers (cont.) Microcomputers: A computer with a microprocessor and its central processing unit is known as a microcomputer. When supplemented with a keyboard and a mouse, microcomputers can be called as personal computers. A monitor, a keyboard and other similar input output devices, computer memory in the form of RAM and a power supply unit come packaged in a microcomputer. These computers can fit on desks or tables and serve as the best choices for single-user tasks.

Personal ComputersPersonal computers come in a variety of forms such as desktops, laptops and personal digital assistants.

Desktops: A desktop is intended to be used in a single location and are widely popular for daily use in workplace and home. Laptops: Similar in operation to desktops, laptop computers are miniaturized and optimized for mobile use. Laptops run on a single battery or an external adapter that charges the computer batteries. They are enabled with an inbuilt keyboard, touch pad acting as a mouse and a liquid crystal display.Personal Digital Assistants (PDAs): It is a handheld computer and popularly known as a palmtop. It has a touch screen and a memory card for storage of data. PDAs can also be effectively used as portable audio players, web browsers and smart phones. Most of them can access the Internet by means of Bluetooth or Wi-Fi communication.

Computer Speak• Did you know that everything a computer does is

based on ones and zeroes? A computer represents data using the binary system/binary code. Data can be text, numbers, pictures, audio, and nearly any other form of information that can be converted into a string of bits, or binary digits, each of which has a value of 1 or 0. The most common unit of storage is the byte (8 bits.) A piece of information can be handled by any computer whose storage space (hard drive ) is large enough to accommodate the binary representation of the piece of information, or simply data.

Computer Speak (cont.)

Each 1 and each 0 is called a bit, each byte makes up a letter or number and when added together bytes the make up various units of measurements.

• 8 bits make a byte• Kilobytes - 1,024 bytes• Megabyte - 1,048,576 bytes• Gigabytes - 1,024 megabytes• Terabytes - 1,024 gigabytes

Computer Speak (cont.)

Nowadays RAM, and storage capacity are all measured in units and users are often confused. So what’s the difference? • RAM is the speed at which your computer runs, the

more gigs of RAM you have the faster your computer will run.

• Hard drives, flash drives, and memory cards are all examples of storage devices. Each of these devices stores data and have various storage capacity. Your computer hard drive might be 160 gig, where as the memory card in your cell phone is 16 gig.