What is HTML5?When you hear HTML, you may think of web sites and web pages and the underlying code used to mark up the content displayed on those pages. Yet HTML5 is far more than a simple markup coding language - rather, it’s a variety of new (and old) technologies that are bundled under the same label. This generation provides new features that enables more robust web applications and formally documents a number of defacto standards that have been in use for years. It does introduce new “tags” for marking up content:
- Semantic tags - <section>, <nav>, <article>, <aside>, <hgroup>, <header>, <footer>, etc. The advantage of using these specific tags is that search engines will be able to more efficiently and accurately index your web content.
- Multimedia tags - <video> and <audio> for embedding such content without the use of any third-party plugins.
- input types e.g. telephone, url, email, date, etc.. Many of these new types bring more meaningful value to the input, which will help with accessibility and allow the web browser to provide a better and more consistent user interface when used.
- New attributes for the <input> tag include autofocus, required and placeholder. Autofocus provides an easier way to set focus to a specific field on a form, required is self-explanatory, and placeholder allows the page author to provide a hint to the end user for filling in the field.
- <font>, <center> and <u> as each of these serve only presentational use better handled by CSS.
- <frame> and <frameset> because their usage negatively affects web accessibility and overall usability.
- Changes in video encoding standards so that video can be viewed across all kinds of devices
- New methods for font embedding so that your brand can be more closely represented online
- 2D drawing using the <canvas> tag
- Improved browser DOM (Document Object Model)
- An offline data store, allowing a web application to persist data in local storage with of course the “same origin” security policies in place.
- Geolocation with consent from the user allows a web application to find the location of the user allowing developers to more readily contextualize content to their specific location.
- How markup errors are handled.
- Web Workers, a standard for support of placing long running processes into the background without locking up the web browser.
- Microdata functionality that provides a means of embedding semantic meaning into existing tags.
- Web Sockets which can best be described as Ajax on steroids.