HTML5 and CSS Flexbox Essentials

Definition: The latest version of HTML, designed to structure content on the web.
Key Features:
- New Elements: Introduces semantic elements like <article>, <section>, <header>, <footer>, <nav>, and <aside>.
- Audio and Video Support: Uses <audio> and <video> tags for media without external plugins.
- Form Enhancements: New input types (e.g., date, email, url) and attributes (e.g., placeholder, required).
- Canvas API: <canvas> element for drawing graphics on the fly via JavaScript.
- Local Storage: Web Storage API to store data locally in the user's browser.

Definition: A layout model that provides a more efficient way to arrange and align items in a container.
Key Properties:
- Container:
  - display: flex;: Enables flexbox on the container.
  - flex-direction: Defines the direction of the flex items (e.g., row, column).
  - justify-content: Aligns items along the main axis (e.g., flex-start, center, space-between).
  - align-items: Aligns items along the cross axis (e.g., stretch, flex-start, flex-end).
- Items:
  - flex-grow: Defines the ability for a flex item to grow if necessary.
  - flex-shrink: Defines the ability for a flex item to shrink if necessary.
  - flex-basis: Defines the default size of an element before the remaining space is distributed.

Definition: The sixth edition of the ECMAScript standard, introducing new features for modern JavaScript.
Key Features:
- Let and Const: Block-scoped variables; let for mutable variables, const for constants.
- Arrow Functions: Shorter syntax for function expressions (e.g., const add = (a, b) => a + b;).
- Template Literals: Multi-line strings and string interpolation using backticks (`Hello, ${name}`).
- Destructuring Assignment: Unpacking values from arrays or properties from objects (e.g., const {name} = person;).
- Modules: Support for modular programming with import and export statements.
- Promises: Simplified asynchronous programming using .then(), .catch(), and async/await syntax.

Definition: Interaction with the Document Object Model (DOM) to dynamically change the content and structure of web pages.
Key Methods:
- Selecting Elements:
  - document.getElementById(): Selects an element by its ID.
  - document.querySelector(): Selects the first matching element with a CSS selector.
  - document.querySelectorAll(): Selects all matching elements as a NodeList.
- Manipulating Elements:
  - Changing Content: element.innerHTML, element.textContent to modify content.
  - Changing Styles: element.style.property to change CSS styles directly.
  - Adding/Removing Classes: element.classList.add(), element.classList.remove().
- Event Handling:
  - element.addEventListener(): Attaches an event handler to a specified element.
  - Common events: click, mouseover, keydown.
Creating Elements:
- document.createElement(): Creates a new element.
- parentElement.appendChild(): Appends a new child element to a parent.

Latest version of HTML for structuring web content.
Introduces semantic elements like <header>, <footer>, <article>, <section>, <nav>, and <aside>.
Supports audio and video with <audio> and <video> tags, eliminating the need for external plugins.
Enhancements in forms with new input types such as date, email, and url, along with attributes like placeholder and required.
Features a Canvas API with <canvas> element for dynamic graphics rendering through JavaScript.
Local Storage allows data to be stored in a user's browser via the Web Storage API.

A modern layout model facilitating efficient arrangement and alignment of items in a container.
To enable flexbox, set display: flex; on the container.
flex-direction determines the layout direction of flex items (e.g., row or column).
justify-content aligns items along the main axis (options: flex-start, center, space-between).
align-items manages alignment along the cross axis with options like stretch, flex-start, and flex-end.
For flex items, flex-grow controls growth ability, flex-shrink manages shrinkage, and flex-basis specifies the default size.

The sixth edition of ECMAScript introducing key features for modern JavaScript development.
Includes let and const for block-scoped variable declarations; let for mutable, const for immutable variables.
Arrow Functions provide a concise syntax for functions, e.g., const add = (a, b) => a + b;.
Template Literals facilitate multi-line strings and string interpolation using backticks (e.g., `Hello, ${name}`).
Destructuring Assignment allows unpacking values from arrays or objects, e.g., const {name} = person;.
Supports modular programming with import and export statements for better code organization.
Simplifies asynchronous coding using Promises, .then(), .catch(), and async/await syntax.

Interaction with the Document Object Model (DOM) to modify webpage content and structure dynamically.
Use document.getElementById() to select an element by ID.
Leverage document.querySelector() to select the first element that matches a CSS selector.
Use document.querySelectorAll() for selecting all matching elements, returned as a NodeList.
Change content with element.innerHTML and element.textContent.
Modify styles directly using element.style.property.
Manage class attributes with element.classList.add() and element.classList.remove().
Attach event handlers via element.addEventListener() for events like click, mouseover, and keydown.
Create new elements using document.createElement() and append them to a parent with parentElement.appendChild().