Structure of operating system

Duration: 5 min

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Module outline

  1. Communication Round: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Direct and Indirect Speech, Active Passive Voice (Voice), Verbal Analogy (Word Based Analogy), Articles, Preposition, Conjunction, Sentence Construction, English Writing Ability, Communication Assessment
  2. Quantitative Aptitude: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Speed Time and Distance, Percentage, Average, Powers and Exponents (Surds and Indices), Time and Work, Mensuration and Geometry, Age Problems, Pipe and Cistern, Probability, Profit and Loss, Simple Interest and Compound Interest, Algebra
  3. Analytical and Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Directions (Direction Test), Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Logical Sequence Of Words, Puzzle Solving (Puzzles), Syllogisms, Seating Arrangements, Calendar, Clock, Blood Relations, Cubes & Dices, Venn Diagram, Analytical Reasoning (Counting Figures Reasoning)
  4. Cognizant Gaming Aptitude: Gamified / Game Based Aptitude
  5. Java (Cluster 1): Java
  6. ANSI SQL MySQL (Cluster 1,2,3): SQL
  7. HTML, CSS, JavaScript (Cluster 1,3): HTML, CSS, JavaScript
  8. Python (Cluster 2): Python for Placements by Yash Sir
  9. Cloud Fundamentals (Cluster 2): Emerging Tech Trends
  10. C# (Cluster 3): C#
  11. OOPs: Object Oriented Programming (OOPS)
  12. Technical Assessment (Coding): Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Pseudo Codes
  13. Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  15. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  16. Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video lecture covers the "Structure of Operating System," contrasting the "Simple Structure" with the "Layered Approach." The instructor explains that while partitioning tasks into modules is common, many systems like MS-DOS evolved from simple beginnings without strict structures. He then details the layered approach, where the OS is broken into pieces with hardware at the bottom and the user interface at the top, utilizing information hiding for modularity.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor starts by reading from the slide titled "Structure of Operating System." He discusses the first bullet point about partitioning tasks into modules. He then focuses heavily on the "Simple Structure" section. He explains that many operating systems do not have well-defined structures and often started as small, simple, and limited systems before growing beyond their original scope. He explicitly mentions "MS-DOS is an example of such a system." To illustrate this, he draws a red diagram on the screen consisting of a large rectangle with smaller rectangles inside, representing a simple, unstructured collection of components. He underlines the phrase "Simple Structure" and the text "MS-DOS" to emphasize these key concepts.

  2. 2:00 – 5:00 02:00-05:00

    The lecture transitions to the "Layered Approach." The instructor explains that with proper hardware support, operating systems can be broken into pieces while retaining control. He discusses how implementers have more freedom in changing inner workings and creating modular systems. He describes a top-down approach where overall functionality is determined and separated into components. He emphasizes the importance of "information hiding," which leaves programmers free to implement low-level routines. Visually, he draws concentric circles on the slide to represent the layers. He labels the innermost circle "layer 0, hardware" and the outermost circle "layer N, user interface." He draws arrows between the layers to show the flow of control, illustrating how higher layers interact with lower layers.

  3. 5:00 – 5:04 05:00-05:04

    The video ends shortly after the instructor finishes drawing the layered diagram. The slide remains visible, showing the concentric circles labeled "A layered operating system." The instructor is visible in the bottom left corner, gesturing as he concludes his explanation of the layered structure. The text on the slide reinforces that the bottom layer is hardware and the highest layer is the user interface.

The lesson effectively contrasts two structural models: the simple, often unstructured growth of early systems like MS-DOS versus the organized, modular nature of layered systems. The instructor uses visual aids, such as drawing boxes for simple structures and concentric circles for layered systems, to make abstract concepts concrete. The progression moves from the limitations of simple structures to the benefits of the layered approach, such as information hiding and modularity. This provides a foundational understanding of how operating systems are architecturally designed to manage hardware and software resources efficiently.

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