HTML5 have native feature for audio and video facility and for it you do not need to have flash.
There are two tags <audio> and <video> it is very simple to add media in your website for it you just have to set the source path. Both tags have their useful attribute, which provides users more feature and make work easy.
Before HTML5, there is no such HTML feature like this to add audio and video. Its support all major browser including IE9+
The videos which are supported by video tag are still in HTML5 draft but mostly used video formats are
Video tag has some attribute which is very helpful for your media-
Example for video tag -
<video src="video.ogg" width="200" height="180" controls>
Your browser does not support the <video> element.