Introduction to Computer Science

Introduction to Computer Science

• Course presented by Dr./Safynaz AbdEl-Fattah Sayed, Computer Science, Beni-suef University

What is a Computer?

• No single, universally agreed-upon definition exists, however, a common understanding is:
• An electronic device receiving input data, processing it by performing mathematical and logical operations, storing large amounts of data and information, and retrieving it as needed (output), all at high speed and with infinite precision

Computer Characteristics

• Composed of interconnected parts functioning collectively
• Relies on input devices for data acquisition
• Processes data using instructions provided by software (mathematical and logical operations)
• Displays processed data using output devices
• Stores data using high capacity storage devices
• Can be connected to form a network to share resources, data, and programs

Comparison of Humans and Computers

Stages of Computer Development

• Early Historical Stage (2000 BC):

  • First attempts to create machines for easier mathematical operations
  • Abacus (manual counting device), still used today to introduce math concepts to children

• Mechanical and Electromechanical Stage (1643 AD):

  • Blaise Pascal invented a semi-automatic calculating machine
  • Consisting of rotating disks for addition and subtraction

• 1944 AD (The Second Stage):

  • Aiken and Grace Hopper, with IBM's assistance developed Mark-1
  • First electromechanical computer

• Modern Computer Generations:

  • Computers developed in several stages since their inception, denoting their continuous progress and evolving design using diverse accessories.
  • Computers are categorized by generation according to similar technologies used in their manufacturing and have commonly seen improvements in certain characteristics, such as speed.
  • Modern computer development is divided into five generations

The Evolution of Computers

• First (1940-1956): Vacuum tubes; large and expensive; e.g., ENIAC, EDVAC, UNIVAC

  • Uses vacuum tubes for logical operations
  • Creates significant heat due to high electrical consumption.
  • Larger size, high operation costs, lacks in speed and versatility, e.g. ENIAC, UNIVAC

• Second (1956-1963): Transistors; smaller and more energy-efficient

  • Replaces vacuum tubes with more energy efficient transistors
  • Smaller size compared to first-generation computers
  • High reliability and speed compared to first generation computers
  • Still produce considerable heat

• Third (1964-1971): Integrated circuits; smaller, faster, and more efficient;

  • Based on Integrated Circuits (ICs);
  • Transistors are placed on silicon chips;
  • High performance; low costs;

• Fourth (1971-2012): Microprocessors: smaller, cheaper, and more powerful;

  • Computers use microprocessors (CPU on a single chip) leading to miniaturization.

• Fifth (1995-Present): Portable smart devices; high productivity;

  • Introduction of multicore processors resulted in much faster operation
  • The generation is based on increased productivity due to the use of multicore processors
  • This generation is marked by high speeds and the communication revolution using widespread devices such as smartphones, laptops, etc

Computer Classification

• Embedded: Specific tasks/functions; embedded within other devices

  • Household appliances, thermostats, cars

• Mobile Devices: Small-sized; computing/Internet capabilities

  • Smart phones, smart watches, handheld gaming devices

• Personal Computers: Single-user systems

  • Desktop, laptops, tablets, smartphones, wearables

• Midrange Servers: Medium-sized, multiple-user networks

• Mainframes: Powerful; managing large volumes of data;

  • Large corporations, government, universities

• Supercomputers: Fastest, most expensive; complex tasks;

  • Used in scientific research, space exploration

Personal Computer System Parts

• System Unit: Case containing the computer's core components

• Display Device:

  • Graphics Card: converting digital data to images
  • GPU: Performs image/graphic processing
  • Monitors/Screens: Displaying the processed data as visual output

• Keyboard: Input device for text input

• Mouse: Input device for controlling on-screen objects

• Hard Disk Drive: Primary storage device inside the system unit

• Optical Drives: Store data on CDs, DVDs, and other optical media

• Sound Card and Speakers: Output sound

Data versus Information

• Data: Known facts, often recorded; raw (unprocessed)
• Information: Result of processing data; meaningful output
• Types of Data:
  • Structured: relational databases
  • Semi-structured: documents, email messages
  • Unstructured: HTML pages, etc

Data Files

• Document Files: Created using word processors, for documents such as reports, memos, term papers, and letters

• Worksheet Files: Created using electronic spreadsheets, for budgets, predictions etc

• Database Files: Created using database software, for highly structured and organized data

• Presentation Files: Created using presentation graphics software, for preparing presentation materials

Computer Components

• Hardware: The physical components of the computer
• Software: Collection of programs controlling the computer's operations