In HTML4 we can get many elements that never used by any webmaster with the purpose which they were planned to, these elements are removed or rebuilt in HTML5.

Here we have discussed about some elements which are new or rebuilt in HTML5.

Canvas element: <canvas> tag is new in HTML5 and it is use to draw graphics, on the fly, via JAVA script (Usually).

Article element: <article> tag is identifies solely, self contained content. This tag allows you to mark particular part of your layout. This tag will have positive impact on SEO like in Forum Post, Blog post, News Story, Comment

Form element: <form> tag is used to create an HTML from for users input, it has contained few more elements like <input>, <text area>, <button>, <select>, <option>, <output>, <label> etc...   This tag has some new elements and some of HTML4 elements are not supported in HTML5.

Hello...
In new HTML5 the new things present are:-

1)Video - HTML5 allows developers to embed video directly in to a web page without using a plugin. With HTML4 the best way to embed video was using Flash – however with HTML5 that's not necessary – this makes it very attractive for developers.

2)Geo location – An important feature which will be used in many mobile web-apps, the geolocation feature enables the site to locate the user, either by GPS (in mobile phones, iPads etc...), by IP Address (for desktops) and also via Wi-Fi and Bluetooth.
Thnx...