Lecture 2

• Central Processing Unit (CPU)

  The most important component of a computer system that performs data input/output, processing and storage functions. It can be installed into a CPU socket on the motherboard.
• Different Parts of CPU

  • Memory or Storage Unit
  • Control Unit
  • ALU (Arithmetic Logic Unit)
• Memory Unit

  Stores and transfers data and instructions to and from other units of the computer. Also known as RAM or primary storage.
• Control Unit


  Manages and coordinates the operations of all parts of the computer. Fetches, decodes and executes instructions from the memory unit.
• ALU (Arithmetic Logic Unit)


  Performs arithmetic and logical operations on data. Has an arithmetic section for operations like addition, subtraction, multiplication, division, and a logic section for operations like selecting, comparing, matching, and merging data.
• Function of CPU

  1. Fetch

  2. Decode

  3. Execute

  4. Store
• Types of CPU

  • Single Core CPU
  • Dual-Core CPU
  • Quad-Core CPU
• Single Core CPU

  Oldest type of CPU with a single core that can only process one operation at a time. Not suitable for multitasking.
• Dual-Core CPU

  Contains a single integrated circuit with two cores, each with its own cache and controller. Can work faster than single-core processors.
• Quad-Core CPU

  Contains two dual-core processors in a single integrated circuit. Increases overall speed and performance without boosting clock speed.
• Computer Hardware Components

  • Input Devices
  • Output Devices
  • Storage Devices
  • Internal Components
• Input Devices


  • Keyboard
  • Mouse
  • Scanner
  • Track Ball
• Output Devices


  • Monitor
  • Printer
  • Speakers
• Storage Devices


  • CD (Compact Disc)
  • DVD (Digital Video/Versatile Disc)
  • Hard Disk
• Computer Software


  Assembly of instructions to the computer to get some work as an output. Typically written in high-level programming languages and converted to machine-understandable language via a compiler or interpreter.
• Software can also be written in low-level languages using an assembler.
• The design and implementation of software vary depending on its complexity, use, and purpose.
• Data structures and algorithms are efficient for creating software.
• Types of Software

  • Application Software
  • Malware or Malicious Software