What is Operating System

Duration: 10 min

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Inside: a video lesson and guided study material.

Module outline

  1. General Intelligence & Reasoning: Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Syllogisms, Venn Diagram, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Data Sufficiency, Puzzle Solving (Puzzles), Data Arrangement, Cubes & Dices, Calendar, Clock, Arithmetic, Number System, HCF LCM, Verbal Analogy (Word Based Analogy), Visual Recognition and Figure Completion, Paper Folding and Cutting, Transformation of Shapes, Clocks and Calendars, Direction Sense, Cubes and Dice, Patterns in Two-Dimensional Figures, Seating Arrangements, Analogy and Classification, Logical Deduction and Induction, Alphabet and Word Tests, Mathematical Operations, Series Completion, Simplification and Approximation, Coding and Decoding, Numerical Reasoning, Assembling and Grouping of Shapes, Three-Dimensional Patterns and Visualization, Vocabulary, Number System, Averages, Mixtures and Alligation, Simple and Compound Interest, Percentages, Algebra, Speed, Time and Distance, Seating and Arrangement Puzzles, Traverse Surveying, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Reading Comprehension, Critical Reasoning, Permutations and Combinations, Narrative Sequencing, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Ratio and Proportion, Time and Work, Mensuration, Data Interpretation, Powers, Surds and Logarithms, Sequences and Series, Articles and Determiners, Sentence Completion, Data Sufficiency, Blood Relations, Simple Interest and Compound Interest, Mixture and Alligation, Sequence and Series (Series), Speed Time and Distance, Algebra, Profit and Loss, Powers and Exponents (Surds and Indices), Permutation and Combination
  2. General Awareness: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, Environment, Static General Knowledge, GK- Current Affairs, Artificial Intelligence, MS Office Applications, Terms & Abbreviations, Keyboard Shortcuts, Evolution of Indian Banking (Banking & Financial Awareness), Emerging Tech Trends
  3. Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Probability, Statistics, Signal Space and Optimum Detection, Probability, Statistics
  4. Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep, Number Systems and Codes, Registers and Counters, Boolean Algebra and Logic Gates, Microprocessors and Microcontrollers, Logic Families and CMOS Logic, Microprocessors, Logic Gates and Boolean Algebra, Minimization of Boolean Functions, Timing, Hazards and Testing, Logic Families, Combinational Logic Design, Arithmetic Circuits, Waveform Generators and Timer Circuits, Semiconductor Memories and Programmable Logic Devices, Combinational Logic Circuits, Latches and Flip-Flops, Finite State Machines, Sequential Circuits and State Machines, Minimization of Boolean Functions, Arithmetic Circuits, Latches and Flip-Flops, Number Systems and Codes, Registers and Counters
  5. Computer Organisation & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer, Register Transfer and Microoperations, Semiconductor Memories and Programmable Logic, Processor Organization and Instructions, Memory Hierarchy and Input/Output, Registers and Counters
  6. Programming & Data Structures: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, HTML Basics, OOPS with C++, Java, Object Oriented Technology
  7. Databases: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization
  8. Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
  9. Theory of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Complexity Theory
  10. Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  11. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Security, Windows OS, Distributed Systems, Unix OS, Linux OS
  12. Computer Networks: Introduction to CN, 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, Data Communication, Website, Browser & Services, Web Design & Development, Network Security, Cyber Threats and Malware Attacks, Cyber Safety and Security
  13. Full Length Mock Tests:
  14. Sectional Tests:
  15. Paper 2 - Full-length Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This lecture introduces the fundamental concept of an operating system (OS) as a core component of computer architecture. The instructor begins by defining the OS as an interface between the user and the core machine, using real-world analogies such as a car's steering wheel, a fan switch, and electronic device buttons to illustrate how an interface mediates interaction. The lecture then transitions to a formal definition, describing the OS as a program or system software that acts as an intermediary between users and hardware. A key role of the OS is presented as a resource manager or allocator, which controls and coordinates hardware resources like CPU time, memory, and system buses among various application programs. The lecture concludes by presenting an abstract view of a computer system, showing the layered architecture where hardware sits at the base, the OS acts as a platform above it, and user applications and compilers reside on top. Market share data for personal computer operating systems (Windows 82.7%, Mac 13.23%, Linux) and mobile phone operating systems (Android 87.5%, iOS 12.1%) is provided to contextualize real-world examples.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The lecture opens with a numbered agenda list on the left side of the screen, covering topics from 'What is Operating System' through 'Micro-Kernel approach' and 'System call.' The instructor introduces the core concept by displaying a slide titled 'What is Operating System,' which states that whatever is used as an interface between the user and the core machine is the OS. Real-world examples are shown, including a car steering wheel marked with red arrows, a ceiling fan next to a hand holding a remote circled in red, and a microwave oven. The instructor poses the guiding question of why an operating system is needed, answering that it enables everybody to use hardware in a convenient and efficient manner.

  2. 2:00 – 5:00 02:00-05:00

    The instructor continues explaining the interface concept using the same slide with the Ford steering wheel, ceiling fan remote, and electronic button panel. The lecture then transitions to a new slide titled 'Definition of Operating System,' which formally defines the OS as a program or system software that acts as an intermediary between the user and hardware. A cartoon boy and desktop computer are shown beside this definition. The instructor hand-draws a box labeled 'OS' with arrows connecting the user side to the computer, visually illustrating its intermediary role. This section bridges the intuitive interface analogy with a more technical software definition.

  3. 5:00 – 9:32 05:00-09:32

    The lecture introduces the OS as a 'Resource Manager/Allocator,' listing CPU time, memory, and system buses as managed resources, paired with a multi-armed manager graphic on a teal background. The slide states that the OS controls and coordinates the use of resources among various application programs. An 'Abstract View of a Computer System' is then presented, showing a layered architecture with Computer Hardware at the base, Operating System in the middle as a platform, and user applications and compilers above. The section concludes with market share examples: for personal computers, Microsoft Windows (82.7%), Mac (13.23%), and Linux; for mobile phones, Android (87.5%) and iOS (12.1%).

The lecture follows a clear pedagogical progression from intuitive analogy to formal definition to architectural role. It begins by grounding the abstract concept of an OS in familiar physical interfaces (steering wheel, fan switch), making the idea accessible before introducing technical terminology. The transition from 'interface' to 'program or system software' marks the shift from analogy to definition. The resource manager concept then explains the OS's functional purpose, while the layered architecture diagram provides a structural view of where the OS sits in the computer system. The market share data serves as a practical anchor, connecting theoretical concepts to real-world products students encounter daily. The teaching flow moves from what an OS is (interface), to how it is defined (system software), to what it does (resource management), and finally where it fits (layered architecture).

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