How can I make a certain video play on the web...??

the thing is that is on a link form.. whenever i click that link.. it should play the video.. not download..

I have no idea on how to make this function work.. since the browser and system updates..

I am trying to play an mp4 format..

the code goes like this..

<a href="movie.mp4">Stream</a>
previously.. this code works.. when i click this.. it opens up a blank page.. and play it there.. now.. it only
downloads the file directly...

how can i make this thing work?? any tips??