Understanding Operating Systems and Computer Networks

Posted on Mar 24, 2025 in Technology

Key Concepts and Definitions

1. Matching Terms:

  • Hardware: Provides basic computing resources.
  • Operating System: Controls and coordinates the use of hardware among various application programs for various users.
  • Applications Programs: Define the ways in which system resources are used to solve users’ computing problems.
  • Users: People, machines, other computers.
  • System Resource: Any physical or virtual component of limited availability within a computer system.

2. Single-Word Examples:

  • User: People.
  • Hardware: CPU.
  • Operating System: Linux.
  • Software: Compiler.

Networking Devices and Their Functions

3. Networking Table:

  • A Modem: (d) Modulates and demodulates data into a digital or analog signal.
  • A Repeater: (f) Sends the digital signal further on in the network.
  • A Bridge: (g) Connects networks and sends data packets between them.
  • A Router: (h) Connects networks that use the same protocol.
  • A Gateway: (a) Is an entrance to another network.
  • A Switch: (b) Channels incoming data but maintains bandwidth speed.
  • A Hub: (e) Channels incoming data but shares bandwidth among devices on a network.
  • A Wireless Access Point: (c) Allows wireless devices to connect to the network.

Operating System Questions and Sentence Completion

4. Questions from the Study Material:

A system that works with a single core: MS-DOS

5. Sentence Completion:

I think you (1) should… A (2) LAN… (3) equipment… (4) WiFi… (5) recommend… (6) remote… (7) VPN… (8) Internet…

Network Types and Their Uses

6. Network Definitions (PAN, WAN, MAN, VPN, WLAN):

  • PAN (Personal Area Network): Home/Office.
  • WAN (Wide Area Network): Country.
  • MAN (Metropolitan Area Network): City/Campus.
  • VPN (Virtual Private Network): Anywhere.
  • WLAN (Wireless Local Area Network): Local Area.

Types of Operating Systems

Simple Batch Systems

  • Reduces setup time by batching similar jobs.
  • First rudimentary operating system.
  • Problem: Slow Performance – I/O and CPU could not overlap; card reader very slow.
  • Solution: Off-line operation – speed up computation by loading jobs into memory from tapes, with card reading and line printing done off-line.
  • Better Solution: Spooling – Simultaneous Peripheral Operation On-Line.

Multiprogrammed Batch Systems

  • Problem: Process execution consists of a cycle of CPU execution (CPU burst) and I/O wait (I/O burst). How can we utilize the CPU more efficiently?
  • Solution: Several jobs are kept in main memory simultaneously, and the CPU is multiplexed among them.

Time-Sharing Systems – Interactive Computing

  • Problem: Batch systems with multiprogramming are efficient from the CPU’s point of view but not necessarily from the user’s.
  • Solution: Use multiple I/O devices (CRT, Keyboard) and time-share.

Personal Computer Systems

  • Personal computers – computer system dedicated to a single user.

Parallel Systems

  • Multiprocessor systems with more than one CPU in close communication.
  • Distributed systems with more than one CPU in communication.

Real-Time Systems

  • Often used as a control device in dedicated applications such as controlling scientific experiments, medical imaging systems, industrial control systems, automobiles, robotics, weapons, etc.

Operating System Fundamentals

What is an Operating System?

It is a program that acts as an interface between application programs and hardware resources.

What Responsibilities Does It Have?

An operating system performs all the basic tasks like file management, memory management, process management, etc.

What Types of Operating Systems Are There?

  • (a) Batch OS
  • (b) Time-Sharing OS
  • (c) Distributed OS
  • (d) Network OS
  • (e) Real-time OS
  • (f) Hard Real-Time OS
  • (g) Soft Real-Time OS

Who Are They For?

  • Batch OS: Users don’t interact with the computer directly. It is for businesses that need to process large amounts of data.
  • Time-sharing: A technique that enables many people at various terminals to use a particular computer system simultaneously.
  • Distributed Operating System: Uses multiple central processors to serve multiple real-time applications and multiple users.
  • Network Operating System: Runs on a server and provides the server the capability to manage data, users, groups, security, applications, and other networking functions.
  • Real-Time Operating System: A data processing system in which the time interval required to process and respond to inputs is so small that it controls the environment.

Software Platforms, Cache, RAM, and Virtual Memory

What is a Software Platform? How is This Different from an OS?

A software environment used to write and run applications. It includes software tools such as GUI builders and compilers. An OS is pre-software, while a platform combines the OS and the CPU.

What is the Cache? Why is it Necessary?

A cache is a place to store something temporarily in a computing environment. In computing, active data is often cached to shorten data access times, reduce latency, and improve I/O.

What is RAM? What is the Difference Between DRAM and SRAM?

RAM (Random Access Memory) is where the OS, application programs, and data in current use are kept so the device’s processor can quickly reach them.

  • DRAM: Requires data to be refreshed periodically to retain the data.
  • SRAM: Does not need to be refreshed, as the transistors inside hold the data as long as the power supply is on.

What is Virtual Memory?

Virtual memory is a feature of an OS that allows computers to compensate for shortages of physical memory by temporarily transferring ranges of data from RAM to disk storage.