computer science

  Topic: Computer Memory Computer memory is the part of a computer where data and instructions are stored. It helps the computer remember information so that it can be used when needed. Memory is very important for the proper working of a computer. Types of Computer Memory 1. Primary Memory Primary memory is the main memory of the computer. It is directly accessed by the CPU. It stores data temporarily while the computer is working. Examples: RAM (Random Access Memory) and ROM (Read Only Memory) . 2. Secondary Memory Secondary memory is used to store data for a long time. It keeps information even when the computer is turned off. Examples: Hard Disk, Pen Drive, CD, and DVD .

  Topic: Input Devices An input device is a hardware device used to enter data and instructions into a computer. These devices help users communicate with the computer. The computer processes the input and gives the result as output. Types of Input Devices 1. Keyboard A keyboard is the most common input device. It is used to type letters, numbers, and symbols into the computer. Example: Typing a document in a word processor. 2. Mouse A mouse is a pointing device used to move the cursor on the screen. It helps us select, open, and move files or programs. Example: Clicking on an icon to open a program. 3. Scanner A scanner is used to convert printed documents or pictures into digital form so they can be stored in a computer. Example: Scanning a photograph into the computer. 4. Microphone A microphone is used to input sound into the computer. It is often used for voice recording and online communication.

  Topic: Sentence and Its Types A sentence is a group of words that expresses a complete thought. A sentence always begins with a capital letter and ends with a full stop (.) , question mark (?) , or exclamation mark (!) . It usually contains a subject and a verb . Types of Sentences 1. Declarative Sentence (Statement) A declarative sentence gives information or states a fact. It ends with a full stop. Example: She is reading a book. Example: The sun rises in the east. 2. Interrogative Sentence (Question) An interrogative sentence asks a question. It ends with a question mark. Example: Where are you going? Example: Do you like ice cream? 3. Imperative Sentence (Command or Request) An imperative sentence gives a command, advice, or request. Example: Close the door. Example: Please help me. 4. Exclamatory Sentence (Strong Feeling) An exclamatory sentence shows strong feelings such as happiness, surprise, or anger. It ends with an exclamation mark. Example: What a ...

  Topic: Prepositions Prepositions are important words in English grammar. They are used before a noun or pronoun to show the relationship between different words in a sentence. Prepositions usually tell us about place, time, direction, cause, or manner . Types of Prepositions 1. Prepositions of Place These prepositions tell us where something is located. Common examples are in, on, under, behind, between, near, above . Example: The book is on the table. Example: The cat is under the chair. 2. Prepositions of Time These prepositions tell us when something happens. Common examples are at, on, in, during, before, after . Example: The meeting starts at 10 a.m. Example: My birthday is in July. 3. Prepositions of Direction (Movement) These show movement from one place to another. Common examples are to, into, onto, from, through, across . Example: She is going to the market. Example: The boy ran across the road. 4. Prepositions of Manner These show the way or method i...