Z-Index

Duration: 5 min

This video lesson is available to enrolled students.

Return to /learn/BIHAR-STET-COMPUTER-SCIENCE-COMPLETE-COURSE/unit-10-web-development/css/css-text-properties/asset-z-index after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About the course: About the Course
  2. Mathematical Aptitude: Number System, HCF LCM, Divisibility Rules, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Time and Work, Mensuration and Geometry, Simple Interest and Compound Interest, Speed Time and Distance, Age Problems, Mixture and Alligation, Algebra, Powers and Exponents (Surds and Indices), Pipe and Cistern, Trigonometry, Statistics, Data Interpretation, Arithmetic
  3. Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Analogy, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Seating Arrangements, Syllogisms, Venn Diagram, Puzzle Solving (Puzzles), Logical Sequence Of Words, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Analytical Reasoning (Counting Figures Reasoning), Cubes & Dices, Calendar, Clock
  4. General Knowledge: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, GK- Current Affairs, Static General Knowledge
  5. Art of Teaching: Nature, Objectives & Characteristics of Teaching, Learners & Learning Process, Factors Affecting Teaching, Methods of Teaching, Classroom Management & Communication, Teaching-Learning Aids & ICT Integration, Evaluation, Assessment & Measurement, Professional Development & Ethics, Policies, Acts & Contemporary Issues, Curriculum & School Environment, Guidance, Counselling & Mental Health, Inclusive Education & Special Needs, Micro-Teaching & Teaching Skills, Lesson Planning
  6. Environmental Science: Environment
  7. Unit 1 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  8. Unit 2 | COA: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Programming the Basic Computer
  9. Unit 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  10. Unit 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  11. Unit 4 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  12. Unit 5 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management
  13. Unit 6 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Transaction Management, Concurrency Control
  14. Unit 7 | 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
  15. Unit 8 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  16. Unit 9 | Object Oriented Programming: OOPS with C++
  17. Unit 10 | Web Development: HTML Basics, CSS, JavaScript-Basics, XML
  18. Unit 11 | 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
  19. Unit 12 | IoT: Emerging Tech Trends, Cloud Computing
  20. Unit 13 | Artificial Intelligence: Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms
  21. Unit 14 | E-Commerce: Electronic Data Interchange and E-Commerce, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Physical Security and Cryptography Basics, Cyber Safety and Security
  22. Unit 15 | Multimedia: Multimedia
  23. Unit 16 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis, DSA using Python
  24. Full Length Mock Tests — General Paper:
  25. Full Length Mock Tests — Computer Science (Paper II):
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This lecture introduces the CSS z-index property, which controls the stacking order of positioned elements. The instructor explains that z-index only applies to elements with a position value such as relative, absolute, fixed, or sticky, and does not work on static elements. A code example demonstrates that setting z-index: -1 on an image places it behind the text, while positive values bring elements forward. The instructor annotates slides with checkmarks next to valid position values, circles key terms like 'positioned' and 'value', and writes notes indicating top and bottom stack order using positive and negative numbers. The visual output confirms the stacking behavior, showing the image positioned behind the paragraph text.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video introduces the CSS z-index property, explaining that it specifies the stack order of positioned elements. The on-screen text displays 'The CSS z-index Property' and the syntax 'z-index: value;'. The instructor highlights that this property only works on elements with a position value such as relative, absolute, fixed, or sticky. A code example is shown where an image has 'position: absolute;' and 'z-index: -1;', placing it behind the text. The visual output confirms the stacking behavior, with the image appearing behind the paragraph.

  2. 2:00 – 5:00 02:00-05:00

    The instructor continues explaining z-index, annotating the slide with checkmarks next to position values (relative, absolute, fixed, sticky) and writing 'Static' in a circle to contrast with positioned elements. The instructor circles the word 'value' in the z-index syntax and writes notes indicating top and bottom stack order with positive and negative numbers. In the code example, the instructor circles the 'img' selector and the word 'absolute', then points to the z-index value of -1. The on-screen text includes 'Because the image has a z-index of -1, it will be placed behind the text.' The instructor uses a red pen to circle and underline key terms like 'positioned', 'absolute', and '-1'.

  3. 5:00 – 5:01 05:00-05:01

    The final moment of the video shows the completed slide with all annotations in place. The on-screen text displays 'The CSS z-index Property', the definition, the syntax block with annotations for top and bottom stack order, and the code example 'img { position: absolute; z-index: -1; }'. The rendered output shows the image behind the text, confirming the negative z-index behavior. This brief window captures the end state of the lecture's visual explanation.

The central concept is that z-index controls stacking order but only for positioned elements. The key rule is that static positioning does not support z-index, while relative, absolute, fixed, and sticky do. Negative values push elements behind content, positive values bring them forward. The worked example uses an image with z-index: -1 to demonstrate the behind-text effect. The instructor's annotations emphasize the distinction between valid position values and static, reinforcing that z-index is meaningless without a non-static position property.

Loading lesson…