A computer is an electronic programmable device, operating under the control of instructions stored to its own memory that can accept raw data and instruction, manipulation data according to the instruction given, produce information as the output which can be even stored in auxiliary devices for future purpose.
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A computer is an electronic programmable device that follows instruction to do different tasks. It can take in raw data, process it and gives us meaning full result. It can store data for later or future purpose.
The input-output concept
The concept of generating raw data into useful information is called the input-output concept.
I=INPUT:
P=PROCESS:
O=OUTPUT:
S=STORAGE:
Input
Input means the raw data and instructions given to the computer using input device to perform a specific task. Example of Input device: Keyboard, Mouse and Microphone etc.
Example of input:
Image (scanned or uploaded)
To letters and word (typing on keyboard)
Sounds (using a microphone)
Process
Processing means treating data according to the instructions given by the user. Computer follow the instructions to performs task like arithmetic and logical calculations, editing, modifying a document. The data and set of instructions must be loaded in computer’s main memory (RAM) for processing.
Example of Processing
Math Calculations (additions, subtractions, division, multiplication, etc.)
Checking logic (like comparing number)
Editing or modifying (text, document etc.)
Output
Output is the result or information that the computer gives after processing raw data. The output may be in the form of text, sound, image, document etc. & displayed through different kinds of output devices.
Examples of Output:
Text (A written document on the screen)
Sound (Music or voice from speakers)
Image ( A displayed or printed picture)
Storage
Storage is an important feature that makes computers more popular. It allows data and instructions to be saved and retrieved when needed.
Types of Storage:
Temporary Storage (RAM): (Stores data and instructions before processing. The output is temporarily stored in RAM before being displayed to the user.)
Permanent Storage (HDD, SSD, USB, etc.): ( Saves data, instructions, and information for future use. Permanent Storage allow data, instruction and information to be saved and retrieved anytime when needed.)
For General Knowledge
SRAM is faster and more costly than DRAM. Because it works quickly and reliably, it is used for cache memory, which stores frequently used data for quick access. DRAM, which is cheaper and can store more data, is used as the main memory. But since SRAM is much faster, it is the best choice for cache memory.
Characteristics of a Computer
Word Length
Speed
Storage
Accuracy
Diligence
Versatility
Non-Intelligent
Word Length
word length is the number of bits process by the CPU at a time. A word is a fixed-size piece of data that the CPU can move between memory and itself.
· It depends on registers, data bus, and ALU.
· Longer word length means a more powerful computer.
· Computers have word lengths from 8 bits to 64 bits.
· A 64-bit computer can process 64 bits at a same time.
Speed(CPU Speed)
The time taken by computer to perform any task is called speed of the computer. The speed of a computer is measured by clock speed, which tells how fast the processor works.
· It is measured in Hertz (Hz).
· 1 Hz means 1 cycle per second.
· A 2 GHz processor can perform about 2 billion tasks per second.
STORAGE
Computer has high storage capacity which allows us to store huge amount of data either temporarily or permanently. Storage capacity is measured in bits and bytes (higher units of data storage).
Image
Accuracy
A computer can perform tasks without any errors which is called accuracy. It works perfectly unless the input is wrong or there is a bug in the hardware or software.
· GIGO (Garbage In, Garbage Out): If wrong data is entered, the output will also be wrong.
· Bug: An mistake or flaw in software or hardware that causes incorrect result or unexpected behavior.
Diligence
The computer to perform the same task repeatedly for long period of time without losing accuracy or speed.
· Even if it performs millions of calculations, each one will be precise and error-free.
· Unlike humans, computers do not get tired or distracted.
Versatility
The computer can perform multiple tasks of different types which is called versatility.
· It can handle simple calculations as well as complex logical operations for a long time.
· It can perform different tasks based on the programs given to it.
Non Intelligence
Besides its many features, a computer we can even take non intelligence feature of
computer as limitation due to its lack of intelligence.
➢ It cannot do any task without instruction.
➢ It has no capability to decide.
➢ It doesn’t have feelings or emotion.
