Tech enthusiast and coder. Passionate about AI, gaming, and innovative solutions.

What is a computer ?

 computer is an electronic device that manipulates information, or data. It has the ability to store, retrieve, and process data. You may already know that you can use a computer to type documents, send email, play games, and browse the Web. You can also use it to edit or create spreadsheets, presentations, and even videos.

Hardware vs. software

Before we talk about different types of computers, let's talk about two things all computers have in common: hardware and software.

·         Hardware is any part of your computer that has a physical structure, such as the keyboard or mouse. It also includes all of the computer's internal parts, which you can see in the image below.

·         Software is any set of instructions that tells the hardware what to do and how to do it. Examples of software include web browsers, games, and word processors.

Everything you do on your computer will rely on both hardware and software. For example, right now you may be viewing this lesson in a web browser (software) and using your mouse (hardware) to click from page to page. As you learn about different types of computers, ask yourself about the differences in their hardware. As you progress through this tutorial, you'll see that different types of computers also often use different types of software.

What are the different types of computers?

When most people hear the word computer, they think of a personal computer such as a desktop or laptop. However, computers come in many shapes and sizes, and they perform many different functions in our daily lives. When you withdraw cash from an ATM, scan groceries at the store, or use a calculator, you're using a type of computer.

Desktop computers

Many people use desktop computers at work, home, and school. Desktop computers are designed to be placed on a desk, and they're typically made up of a few different parts, including the computer case, monitor, keyboard, and mouse.

Laptop computers

The second type of computer you may be familiar with is a laptop computer, commonly called a laptop. Laptops are battery-powered computers that are more portable than desktops, allowing you to use them almost anywhere.

Tablet computers

Tablet computers—or tablets—are handheld computers that are even more portable than laptops. Instead of a keyboard and mouse, tablets use a touch-sensitive screen for typing and navigation. The iPad is an example of a tablet.

Servers

A server is a computer that serves up information to other computers on a network. For example, whenever you use the Internet, you're looking at something that's stored on a server. Many businesses also use local file servers to store and share files internally.

Other types of computers

Many of today's electronics are basically specialized computers, though we don't always think of them that way. Here are a few common examples.

·         Smartphones: Many cell phones can do a lot of things computers can do, including browsing the Internet and playing games. They are often called smartphones.

·         Wearables: Wearable technology is a general term for a group of devices—including fitness trackers and smartwatches—that are designed to be worn throughout the day. These devices are often called wearables for short.

·         Game consoles: A game console is a specialized type of computer that is used for playing video games on your TV.

·         TVs: Many TVs now include applications—or apps—that let you access various types of online content. For example, you can stream video from the Internet directly onto your TV.

PCs and Macs

Personal computers come in two main styles: PC and Mac. Both are fully functional, but they have a different look and feel, and many people prefer one or the other.

PCs

This type of computer began with the original IBM PC that was introduced in 1981. Other companies began creating similar computers, which were called IBM PC Compatible (often shortened to PC). Today, this is the most common type of personal computer, and it typically includes the Microsoft Windows operating system.

Macs

The Macintosh computer was introduced in 1984, and it was the first widely sold personal computer with a graphical user interface, or GUI (pronounced gooey). All Macs are made by one company (Apple), and they almost always use the Mac OS X operating system.

 Generations of Computers

Generation in computer terminology is a change in technology a computer is/was being used. Initially, the generation term was used to distinguish between varying hardware technologies. Nowadays, generation includes both hardware and software, which together make up an entire computer system. There are five computer generations known till date. Each generation has been discussed in detail along with their time period and characteristics. In the following table, approximate dates against each generation has been mentioned, which are normally accepted.

First Generation Computers 

The period of first generation was from 1946-1959. The computers of first generation used vacuum tubes as the basic components for memory and circuitry for CPU (Central Processing Unit). These tubes, like electric bulbs, produced a lot of heat and the installations used to fuse frequently. Therefore, they were very expensive and only large organizations were able to afford it. In this generation, mainly batch processing operating system was used. Punch cards, paper tape, and magnetic tape was used as input and output devices. The computers in this generation used machine code as the programming language.

 The main features of the first generation are:

• Vacuum tube technology • Unreliable • Supported machine language only • Very costly • Generates lot of heat • Slow input and output devices • Huge size • Need of AC • Non-portable • Consumes lot of electricity Some computers of this generation were: • ENIAC • EDVAC • UNIVAC • IBM-701 • IBM-750 9

Second Generation Computers

The period of second generation was from 1959-1965. In this generation, transistors were used that were cheaper, consumed less power, more compact in size, more reliable and faster than the first-generation machines made of vacuum tubes. In this generation, magnetic cores were used as the primary memory and magnetic tape and magnetic disks as secondary storage devices. In this generation, assembly language and high-level programming languages like FORTRAN, COBOL were used. The computers used batch processing and multiprogramming operating system.

The main features of second generation are:

• Use of transistors

 • Reliable in comparison to first generation computers

• Smaller size as compared to first generation computer

 • Generates less heat as compared to first generation computers

• Consumed less electricity as compared to first generation computers

 • Faster than first generation computers

• Still very costly

• AC required

• Supported machine and assembly languages Some computers of this generation were: • IBM 1620 • IBM 7094 • CDC 1604 • CDC 3600 • UNIVAC 1108 10

 Third Generation Computers

The period of third generation was from 1965-1971. The computers of third generation used Integrated Circuits (ICs) in place of transistors. A single IC has many transistors, resistors, and capacitors along with the associated circuitry. The IC was invented by Jack Kilby. This development made computers smaller in size, reliable, and efficient. In this generation remote processing, time-sharing, multi-programming operating system were used. High-level languages (FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68 etc.) were used during this generation. 

The main features of third generation are:

 • IC used 

• More reliable in comparison to previous two generations

 • Smaller size

 • Generated less heat 

• Faster 

• Lesser maintenance

 • Costly

 • AC required 

• Consumed lesser electricity 

• Supported high-level language

 Some computers of this generation were: • IBM-360 series • Honeywell-6000 series • PDP (Personal Data Processor) • IBM-370/168 • TDC-316 

FOURTH GENERATION

The period of fourth generation was from 1971-1980. Computers of fourth generation used Very Large Scale Integrated (VLSI) circuits. VLSI circuits having about 5000 transistors and other circuit elements with their associated circuits on a single chip made it possible to have microcomputers of fourth generation. Fourth generation computers became more powerful, compact, reliable, and affordable. As a result, it gave rise to Personal Computer (PC) revolution. In this generation, time sharing, real time networks, distributed operating system were used. All the high-level languages like C, C++, DBASE etc., were used in this generation. The main features of fourth generation are: • VLSI technology used • Very cheap • Portable and reliable • Use of PCs • Very small size • Pipeline processing • No AC required • Concept of internet was introduced • Great developments in the fields of networks • Computers became easily available Some computers of this generation were: • DEC 10 • STAR 1000 • PDP 11 • CRAY-1(Super Computer) • CRAY-X-MP(Super Computer)

Fifth Generation Computer

 The period of fifth generation is 1980-till date. In the fifth generation, VLSI technology became ULSI (Ultra Large Scale Integration) technology, resulting in the production of microprocessor chips having ten million electronic components. This generation is based on parallel processing hardware and AI (Artificial Intelligence) software. AI is an emerging branch in computer science, which interprets the means and method of making computers think like human beings. All the high-level languages like C and C++, Java, . Net etc., are used in this generation. 

 The main features of fifth generation are: 

• ULSI technology 

• Development of true artificial intelligence

 • Development of Natural language processing 

• Advancement in Parallel Processing 

• Advancement in Superconductor technology 

• More user-friendly interfaces with multimedia features 

• Availability of very powerful and compact computers at cheaper rates Some computer types of this generation are:

 • Desktop 

• Laptop 

• Notebook 

• Ultrabook 

• Chromebook

 parts of a computer

Whether it's a gaming system or a home PC, the five main components that make up a typical, present-day computer include:

• A motherboard
• A Central Processing Unit (CPU)
• A Graphics Processing Unit (GPU), also known as a video card
• Random Access Memory (RAM), also known as volatile memory
• Storage: Solid State Drive (SSD) or Hard Disk Drive (HDD)

In terms of construction, each of these main components are attached to the motherboard and then put into a protective case—resembling the clean, polished look most of us are accustomed to seeing. 

Sure, most computers have their own distinct design - and different brands of hardware installed - but the components listed above are standard across all computers. 

Important: A quick note before we dive into the details—I’m listing and talking about the different components of a computer. This is by no means intended to be an invitation to disassemble your computer, nor is it a set of instructions to do so. Without the proper knowledge, you can severely damage your computer, and importantly, doing so is unsafe. 

1. Motherboard

What it is: All components of a computer communicate through a circuit board called the motherboard, as was mentioned above. What it does: Think of the motherboard as the glue that holds everything else together. The motherboard’s video card and Central Processing Unit are contained in an integrated (built-in) chipset, shown in the picture below:

This is where input/output devices such as a keyboard, mouse, and speakers get plugged in.

2. Central Processing Unit (CPU)

What it is: The CPU is often called the "brain" of a computer, thanks to its direct plug connection to the motherboard, and communication with all of the computer’s other components.

What it does: Whenever you write a line of code (in Python, Java, C++, or any other programming language), it's broken down into assembly language—which is a language that the processor can understand. It fetches, decodes, and executes these instructions.

And that’s where the CPU comes in—all the processes a computer handles are taken care of by the CPU.

 

3. Graphics Processing Unit (GPU)

What it is: It's not uncommon to hear gamers obsess over the next new graphics card, as these graphic cards make it possible for computers to generate high-end visuals like those found in the many different types of video games. In addition to video games, though, good graphics cards also come in handy for those who rely on images in order to execute their craft, like 3D modelers using resource-intensive software. What it does: Graphics cards often communicate directly with the display monitor, meaning a $1,000 graphics card won't be of much use if there isn't a high-end monitor connected to it.

 

4. Random Access Memory (RAM)

What it is: RAM, also known as volatile memory, stores data regarding frequently accessed programs and processes. (It's called volatile memory because it gets erased every time the computer restarts.) What it does: RAM helps programs and games start up and close quickly.

5. Storage

What it is: All computers need somewhere to store their data. Modern computers either use a Hard Disk Drive (HDD) or Solid State Drive (SSD).

What it does: HDDs are made of an actual disk onto which data is stored. The disk is read by a mechanical arm. (HDDs are cheaper than SSDs, but are slowly becoming more and more obsolete.)

SSDs (think SIM cards) have no moving parts and are faster than a hard drive, because no time is spent waiting for a mechanical arm to find data on a physical location on the disk.