HTML Development Interview Questions & Answer for Fresher and Experience

What is HTML5, and what are its main features?

HTML5, the fifth iteration of the HyperText Markup Language, is used to structure content on the web and includes numerous enhancements over its predecessor, HTML4. Key features of HTML5 include:

   New semantic elements: Elements such as <header>, <footer>, <article>, and <section> provide clearer context and structure for web pages.

   Multimedia support: Native support for audio and video elements simplifies the integration of multimedia content without relying on third-party plugins.

   Canvas element: This element offers a 2D drawing surface for creating dynamic graphics and animations.

   Geolocation API: Allows websites to access the user's geographical location with their consent.

   Web Workers: Facilitate background processing and parallel execution of JavaScript code without hindering the performance of the main browser thread.

   Local Storage: Provides a more efficient and secure method for client-side data storage.

   Enhanced form elements: Improved input types and validation features lead to a better user experience and easier form management.
What is the difference between the ‘id’ attribute and the ‘class’ attribute of HTML elements?

Multiple elements in HTML can have the same class value, whereas a value of id attribute of one element cannot be associated with another HTML element.
How to optimize website assets loading?

To optimize website load time we need to optimize its asset loading and for that:
CDN hosting - A CDN or content delivery network is geographically distributed servers to help reduce latency.
File compression - This is a method that helps to reduce the size of an asset to reduce the data transfer
File concatenation - This reduces the number of HTTP calls
Minify scripts - This reduces the overall file size of js and CSS files
Parallel downloads - Hosting assets in multiple subdomains can help to bypass the download limit of 6 assets per domain of all modern browsers. This can be configured but most general users never modify these settings.
Lazy Loading - Instead of loading all the assets at once, the non-critical assets can be loaded on a need basis.
What are the different kinds of Doctypes available?

The three kinds of Doctypes which are available:
Strict Doctype
Transitional Doctype
Frameset Doctype
What is the difference between “display: none” and “visibility: hidden”, when used as attributes to the HTML element.

When we use the attribute “visibility: hidden” for an HTML element then that element will be hidden from the webpage but still takes up space. Whereas, if we use the “display: none” attribute for an HTML element then the element will be hidden, and also it won’t take up any space on the webpage.