Basic Computer Operations

Computer Basics

• A computer is an electronic device that can manipulate data, and it is commonly used for technical education and research.
• The components of a computer system include:
  • Input: Accepting data through devices like keyboards and mice.
  • Processing: Performing operations on the data.
  • Output: Displaying the result on devices like printers and monitors.
  • Storage: Storing the result for further use.

Elements of Computer

• Hardware: The physical parts of a computer, such as the keyboard, mouse, and monitor.
• Software: A set of programs and procedures that describe how to use the computer, including:
  • System software: Controls the operations of the computer, such as operating systems and programming languages.
  • Application software: Designed to solve specific problems or perform tasks, such as word processing and spreadsheet software.

Types of Software

• System software:
  • Operating systems: Interface between the user and hardware.
  • Programming languages: Translate instructions into a form that can be executed by the computer.
  • Utility programs: Help users perform maintenance tasks, such as formatting hard disks and taking backups.
• Application software:
  • Word processing software: Enables creating, editing, and printing documents.
  • Spreadsheet software: A numeric data analysis tool that allows users to create a computerized ledger.

Data and Information

• Data: Raw facts and figures, such as numbers.
• Information: Processed data that provides meaning, such as the result of a calculation.

User and Procedure

• User: A person who operates or uses a computer.
• Procedure: A series of steps to perform a specific task, such as using an ATM.

Languages of Computer

• Machine level language: Written in binary code, understood by the computer.
• Assembly language: Uses numeric codes to represent instructions.
• High-level language: Easy to understand and write, such as C and C++.

Translators

• Interpreter: Converts high-level language into machine language, line by line.
• Compiler: Converts high-level language into a low-level language, all at once.
• Assembler: Converts assembly language into machine language.

Microsoft Office

• Word processing software: Enables creating, editing, and printing documents.
• Shortcut keys: Used to perform tasks quickly, such as formatting text and navigating the document.

Auxiliary Storage Devices

• Long-term, non-volatile memory that stores data even when the computer is turned off.
• Types of auxiliary storage devices:
  • Sequential access devices: Data can only be read in sequence, such as cassettes.
  • Random access devices: Data can be accessed directly, such as DVDs and CDs.

Classification of Computers

• Based on size:
  • Supercomputer: Handles complex scientific applications.
  • Mainframe: Contains multiple processors and is used for special purposes.
  • Portable computers: Small and portable, such as laptops.
  • Embedded computers: Built into special devices, such as video games and microwave ovens.
• Based on function:
  • Analog computers: Data varies continuously, used for measuring temperature and pressure.
  • Digital computers: Data is discrete, used for digital watches and calculators.
  • Hybrid computers: Combines analog and digital computers, used for ECG machines.

Parts of Computer

• CPU (Central Processing Unit): Executes instructions and performs calculations.
  • Control Unit: Directs the entire computer system.
  • Arithmetic Logic Unit (ALU): Performs arithmetic and logic operations.
• Memory Unit: Holds data and instructions for processing.
  • RAM (Random Access Memory): Stores data temporarily and is erased when the computer is turned off.
  • ROM (Read-Only Memory): Stores permanent instructions and data.

Operating System

• Interface between the user and hardware.
• Two major objectives:
  • Making the computer system user-friendly.
  • Managing the resources of the computer system.

Classification of Operating Systems

• Based on user interface:
  • GUI (Graphical User Interface): Uses icons and graphics, such as Windows.
  • CUI (Character or Command User Interface): Uses commands, such as DOS.
• Based on functionality:
  • Multi-user: Allows multiple users to run programs simultaneously.
  • Multiprocessing: Supports multiple processes at the same time.
  • Multitasking: Allows multiple programs to run concurrently.
  • Multithreading: Allows different parts of a single program to run concurrently.

Microsoft Excel

• A spreadsheet software that simulates a worksheet.
• Features:
  • Worksheet: A grid made up of rows and columns.
  • Row number: Identifies the horizontal row.
  • Column letter: Identifies the vertical column.
  • Active cell: The current cell where data is entered.
  • Formula bar: Displays the value or formula used in the active cell.

Mathematical Functions

• ABS: Returns the absolute value of a number.
• COUNTIF: Counts the number of cells that meet a given criteria.
• COUNT: Counts the number of cells that contain numbers.
• FACT: Returns the factorial of a number.
• MOD: Returns the remainder of a division operation.
• PRODUCT: Returns the product of a range of numbers.
• POWER: Returns the result of a number raised to a power.
• SUM: Returns the sum of a range of numbers.
• SUMIF: Returns the sum of cells that meet a given criteria.

Logical Functions

• IF: Returns one value if the condition is true, and another value if the condition is false.
• NOT: Returns the opposite of the given value.
• OR: Returns true if any of the arguments are true.
• AND: Returns true if all of the arguments are true.