Introduction to Computers

A computer is an electronic device that manipulates information or "data." It has the ability to store, retrieve, and process data. You can use a computer to type documents, send email, and surf the Internet. 

 You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more.

A computer is any machine that can seem to do useful thinking.

Whether you realize it or not, computers play an important role in our lives. When you withdraw cash from an ATM, scan groceries at the store, or use a calculator, you're using a type of computer.

Data is a collection of unorganized facts, which can include words, numbers, symbols, images and sounds.

Information is processed data that is organized, has meaning, and is useful. Examples are reports, newsletters, a receipt, a picture, a book, etc.

Data entered in to a computer is called input. processing cycle.

The 3 wares

To build a complete computer system, you need hardware, software, and liveware.

Hardware

Hardware simply refers to the visible and tangible parts of a computer or the physical pieces of equipment in a computer system.

Software

The info that the computer deals with is called software, because you can’t feel it: it flows through the computer’s circuits as coded pulses of electricity.

The computer can handle two kinds of software: data (lists of names, addresses, numbers, words, and facts) and programs (lists of instructions that tell the computer what to do).

To feed the computer software (data and programs), you can type on the keyboard, or insert ROM chips or disks containing the software, or let the computer receive the software from another computer (by running wires between the computers or letting the computers chat with each other by phone).

If you feed the computer wrong software — wrong facts or wrong instructions — the computer will print wrong answers. Wrong stuff is called garbage. If you feed the computer some garbage, the computer spits out garbage answers.

If a computer prints wrong answers, the computer might not be broken; it might just have been fed wrong data or programs. If you tell a technician to fix it, the technician might reply, “Hey, the computer’s fine! Don’t blame the computer! It’s your fault for feeding it garbage! If you put garbage in, you get garbage out!” That’s called the principle of garbage in, garbage out (which is abbreviated GIGO, pronounced “guy go”). The technician will say, “it’s just a case of GIGO”.

Liveware

The person sitting at the computer is called the liveware, operator, user, or meathead — because the person’s head is made of meat instead of wires. A person that communicates with a computer or uses the information it generates is called an End user.

For a complete computer system, you need all 3 wares: the hardware (equipment), software (info), and liveware (people).