What is a Computer?
Computer :- A modern high speed electronic device. No more than two or three tasks can be performed with the help of other electronic devices. But with the help of computer, many difficult tasks can be done in a perfect way. The two main characteristics of a computer are that it can store millions of data. It can follow instructions very fast and accurately. The word computer is derived from the Greek word compute.
Basically the word computer means a computing device. (Again, the Latin word computare is derived from the word computer.) In the past, calculations were done only with computers. Computer language is a computer language based on electronic signs. The computer publishes the result based on the instructions given to the computer through computer language. Computer language is computer program. Computers without programs are inert matter. But in the present era due to the versatile use of computer, the definition of computer has become very broad. Computers can no longer be confined to a finite definition.
Definition of computer : - Computer is a set of electrical waveforms that converts its own signals and solves problems with the help of commands applied by the user.
Computer Features : - There are computer features such as accurate results, speed, data storage, automatic display, tolerance, memory, etc.
Use of computer : - from home to office - Court cannot be found at any place where computer is not used, office work, business - commerce, school-college-university, various types of projects. Computers are used in industries, sports, entertainment, shops, bang-in insurance companies, meteorological offices, space stations, etc.
What are the different parts of computer?
The basic part of computer is -
CPU: Central Processing Unit. Processes input and output data and sends it to output.
MONITOR: Displays the processing data through CPU which we see.
Keyboard: The keyboard allows writing, data input, and commands.
Mouse: This allows the CPU to execute various commands.
RAM: Random Access Memory. Temporary memory device.
ROM : Read Only Memory. permanent memory device
USB Port : Input-output data is exchanged.
Motherboard : Connects the CPU, keyboard, mouse, monitor, RAM, ROM, memory card (hard disk drive or solid state drive), graphics card, and various USB ports.
Pen Drive : Pen Drive is a type of memory device. that stores information.
What is an Input and Output Devices?
The working of a computer can be broadly divided into two parts.
- Input Unit: The area of receiving instructions. The keyboard and mouse fall in this area.
- Output Unit: The result display area is the CPU and monitor within this area.
Input Device:
The function of an input device is to communicate with the computer. Any type of data is converted into binary electronics signals (zero and one) and sent to CPU. Because the CPU can't understand anything other than (0, 1).
Output Device:
The electronics signals coming from the input devices are converted into human perceptible image based, alphabet based, math based, word and picture based etc.
What is a Monitor ?
The device without which a computer cannot be imagined is the monitor. Monitor is the display unit. The results of all the commands given by the computer and the actions performed as a result can be seen directly on the monitor. Monitor can be digital or analog. But nowadays analog or black and white monitors are rarely seen. Monitoring technology can be found in both LCD and cathode-ray monitors. Despite being wall clock in size and light in weight, modern technology LCD monitors have not remained popular due to their high prices. There are 14 inch, 15 inch, 16 inch and 21 inch monitors available in the market. Reputed Monitor Manufacturers like Vusonic, NEC, Philips, LG, Goldstar, Hyundai, Samsung, Hranson etc.
What is a Mouse ?
It looks a lot like a mouse, hence it is called a rat. One of the narrow ends is connected directly to its CPU. The top of the mouse has two presses (although many mice have three), the button on the right is called the right button and the button on the left is called the left button. Moving the mouse and arrows when the computer is open is called a mouse pointer. And this movement is called mouse drug. Usually when you want to select the icon of a file or folder, once you press the left mouse button with the mouse pointer, it is called a single click. And to open it, you have to press the left mouse button twice. This double pressing is called double click of the mouse. When you press the button on the right side of the mouse, it is called right click. Right-clicking doesn't usually select or open a file folder, but it does provide a list of prompt menu commands.
The use of a mouse keyboard as an input device is very limited. The operation of the computer has become very easy with the use of mouse. Depending on the strategy the mouse can be divided into two parts. eg.
Mechanical Mouse: Mechanical mouse consists of a small ball. The ball moves when you move the mouse. The ball controls the movement of the cursor by turning two switches on and off through two rollers.
Optical Mouse: Optical mouse does not have a small ball but a light beam instead. This lightbeam controls the movement of the cursor with the help of a special type of mouse pad.
Mice are of two types based on the number of buttons. eg.
- Mouse with two or three buttons (for IBM computers).
- One-button mouse (for Macintosh computers).
Rats can be divided into three categories based on mouse movement detection technology. eg.
- Mechanical Mouse.
- Light Mechanical Mouse.
- Optical mouse.
Mouse can be divided into four categories based on the way the mouse is connected to the computer system:
- Serial Mouse
- Just Mouse
- Proprietary Mouse
- Wireless Mouse
There are two main types of wireless mice:
- Infrared Wireless Mouse and
- Radio signal control wireless mouse.
What is a Keyboard ?
There are 64 to 101 keys on keyboards or 102 keys on some keyboards. The keyboard can be broadly divided into 5 parts on the basis of usage.
(1) function key.
(2) Arrow keys.
(3) Of Alpha Batik.
(4) Numerical key or Logical key.
(5) Special key.
Function Key:
The keys from F1 to F12 on the top left of the key board are called function keys. What is a task called because a specific task can be done. This key is used to help a program, or to run a program.
Arrow Key:
There are four different keys on the bottom right of the keyboard. Some keys are also on the top of the board. The keys are marked with an arrow. Which makes it easy to move the cursor right, left, up and down. These are also called edit keys. Because these keys are also used for text editing.
Alpha Batik Key:
The part of the keyboard where the letters A to Z of the English alphabet are arranged is called the alphabetical section.
Numeric Key or Logical Key:
Number keys from 0 to 9 on the right side of the keyboard are called numeric keys. Also <, >, = are on the board of the logical operator.
Special Key :
Apart from the mentioned keys, other keys on the keyboard are called special keys because they perform certain functions. The following is a description of the properties of special keys.
Esc: This key is used to cancel any instruction.
Tab: This key is used to create paragraphs, columns, numbers, opening paragraphs, etc., as required on the screen.
Caps Lock: This key is used to type lowercase and uppercase text in English.
Shift: This key is used to type upper and lower case in the same word or at the beginning. For example: Dhaka, Khulna To type two words, first press the shift key and then release the next key. This key is used to write the Bengali OR OR alphabet. In addition, various commands are given to the computer by holding down the Shift key as well as the Function key.
Ctrl: With this key the command is given by pressing a special key. For the convenience of the user, there are two keys on the right and left side of the keyboard.
Alt: This key is used in different ways to give different commands to different programs and different commands can be created.
Enter: This key is used to execute instructions on the computer. This key is also used to create new paragraphs for writing.
Pause brake: If it is difficult to read any text on the computer for high speed, then it can be read by pressing this key.
Print Screen: If you want to print everything you see on the computer screen, you must use this key.
Delete: This key is used to delete a sentence or text.
Home: This key is used to move the cursor to the top of the page.
End: Pressing this key will place the cursor or pointer anywhere at the end of the text or page.
Page Up: This key is used to move the cursor upwards.
Page Down: This key is used to move the cursor down.
Insert: When you type something in the middle of a text, it is usually written on the right side of the text, but when you press this key, it overwrites the previous character. When this key is pressed again at the end of the operation, it returns to its previous position.
Back Space: This key is used to delete the previous part of the text.
Space bar: This key is used to give space between words while writing a sentence.
New Look: When this key is pressed, the keys on the right are turned on. There are also 4 more keys on the multimedia keyboard.
As if
Stand By Mood: Pressing this key will keep the computer on but the monitor will turn off.
Mail Key: Pressing this key launches Outlook Express and sends mail with it. However, the Internet must be on.
Web Key: This key can be used to open web browser directly. And the internet can be browsed.
Start Menu Key: This key can be used to open the status menu and create required commands.
What is a Motherboard ?
Motherboard or mainboard is the circuit board inside the computer to which the various devices required by the system are interconnected and new devices are connected. In computing parlance, these devices are called peripherals. Due to the gradual advancement of technology, it is not possible to give a precise definition of motherboard as new peripherals are being added to the motherboard every day.
Motherboard is basically the connection between all the devices in the computer system by bus speed. Previously, many devices were connected to motherboard extension slots. Currently all these devices are built-in with the motherboard. As a result, there is no need to install these devices separately. A Pentium motherboard has bus slots on the top. All these bus slots contain system adapters such as video, sound, networking etc. The other end is fastened with screws. There is a RAM slot on the right side of the motherboard. Also on the motherboard there is a 1/0 card, a floppy drive controller, two IDE chain connectors, a SATA port. Keyboard and mouse connectors, USB port. All these connectors are connected by ribbon cable etc. There are different types of motherboards currently available in the market. Notable among motherboard manufacturers are ASUS, Gigabyte, Intel, ECS etc.
What is a CPU ?
CPU stands for "Central Processing Unit". This is the most important part which performs all the work according to the instructions and gets the result. CPU basically means processor. A processor is a number of devices containing electronic circuits that can verify the information provided by using logic gates to extract comparative information. To perform this task, the part in the middle of the processor is called ALU.
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| CPU |
CPU (Central Processing Unit) is the most important of the organizational parts of the computer. mathematical analysis, logical formatting of all the instructions given by us while working on the computer, controlling and storing the necessary information for a certain period of time; In a word, all the processing work is done in this part. Just as the brain of an animal keeps the body moving by controlling all the functions, similarly the computer CPU keeps the computer active by doing all the tasks. That's why the CPU is called the brain of the computer.
What is a Printer?
A printer is a popular output device for taking computer results printed on paper. The output which is received on the paper through the printer is called hard copy.
Printers can be divided into three main parts:
(1) Character Printer: Prints one character at a time. This type of printer used on PC can print 30 to 600 characters per second with low output. Such as- dot-matrix printers, daisy wheel printers.
(2) Line Printer: Prints one line of text at once. Used for high volume output, this type of printer can print 300 to 3000 lines per minute. Such printers can be used in mini and mainframe computers. Such as: Chain Printer, Drum Line Printer.
(3) Page Printer: Can print one page at a time. Such a printer can print 10 to 300 pages per minute. such as laser printers.
There are two types of printers based on technology.
(4) Impact Printer : Such printers have an electromechanical printing head. Whose hammer or pin strikes the ribbon and prints the text. Such as: dot-matrix printer, daisy wheel printer, chain printer, drum printer, ball printer.
(5) Non-Impact Printer : This printer does not have any printing head. Such printers use thermal, chemical, electrostatic, laser beam or inkjet technology to print text. inkjet printer,
Conventional Printers: Dot Matrix Printers: Dot Matrix Printers are the cheapest as Impact Printers.
But quite popular. This printer has a print head for printing, the print head usually uses a grid of 8, 9, 16 or 24 small pins. How many pins hit the pin head on the ribbon, a certain number of times on the paper
Creates characters by putting dots. Images or characters printed on this printer are not smooth or smooth. This printer can print 30 to 300 characters per second.
Ball Printer: Ball printer is another type of impact printer that has a rotating ball.
On which there is a single character and from here it is printed like a typewriter by hitting the ribbon.
Another type of printer, the daisy wheel printer, is also of the same style. The printing quality of both of them is quite good as each character has a different pattern in it like a typewriter. And they can also be used as typewriters.
Inkjet printers have a liquid ink source inside the ink cartridge. From this source of ink 300-600 nozzles are mounted on the print head. The diameter of the nostrils is less than the diameter of our hair. When the print head comes and goes to the paper that will be printed, droplets of ink come through the nozzle and fall on the paper. The computer determines where this leak will fall.
What is a Memory Unit ?
All the functions of the computer are done by its icht. Although the smallest size of data is registered in iChat for temporary storage, iChat does not have the ability to store basic instructions, complete programs and data.
Only a few bytes of data can be stored in the register. Thousands of bytes to enter programs and data in addition to registers
The computer needs a part, this part is called memory.
That is, the part of the computer that stores programs, data and results is called memory.
The memory of a computer system can be divided into two main parts:
- Primary memory
- Secondary memory
Primary memory The primary memory of a computer is high-speed memory built on semiconductor technology. Primary memory is used to store programs and data during computer operation.
Primary memory can be divided into volatile and non-volatile. Semiconductor memory that loses stored data when the power supply is turned off is called volatile memory. And if the power supply is cut off, all the stored data in the semiconductor memory cannot be erased, it is called non-volatile memory. Primary memory is available in the market in the form of IC and is placed on the main circuit board which is known as the motherboard of the computer. Data can be written to each cell (right) and stored data can be read from the cell. Cells are called spaces. The location where the data is to be stored or the data is to be read is indicated by the serial number of the locations. These serial numbers of locations are called memory addresses.
There are two main types of primary memory:
- RAM
- ROM
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| RAM |
1. RAM : Read/Write memory built in RAM semiconductor technology, that is, the data stored in this memory can be read as well as the data can be written and stored in this memory when needed. The data in this memory can be erased and new data can be saved. RAM is abbreviated as Random Access Memory because data can be read from any location of RAM at any time or data can be written to any location. Also, when the power supply of RAM is increased, all the data is erased, hence RAM is also called volatile memory. RAM can store data as long as there is a power supply. RAM is usually found in the form of chips on small circuit boards, these are called memory modules. RAM modules with capacity of 1 Gay, 2 Gay, 4 Gay, 8 Gay, 8 Gay, 16 Gay, 32 Gay, 64 Gay, 128 Gay and 256 Gay have been used in the computer. Currently 64GB, 128GB and 256GB memory modules are available in the market and are being used in computers.
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| ROM |
2. ROM: ROM is a type of permanent semiconductor memory. This memory is made in the form of IC. The data or programs are saved during creation. Necessary and often necessary programs to start a computer system are stored in ROM. This program is called BIOS. The microprocessor on a computer system first executes the ROM program. The ROM program then creates an environment for other program execution. Once the data is stored in ROM, it is called permanent memory as it cannot be changed. It is also called non-volatile memory because the data in this memory cannot be erased even if the power supply is cut off. The information stored in the ROM can only be read but the user cannot write any information to the ROM, so this memory is called Jabdhaf Nghasu Gabasaratu Jang. The program stored in ROM is called firmware because the manufacturer stuffs the program in it while making the ROM.
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