How to download video from YOUTUBE

Any video from YouTube is easily downloaded by 2 different ways........
 1) Open the video that you want to download from YouTube,
    In that video you see the link in the address bar like this,
    www.youtube.com/zzzzzzzzz
    In this link you have to do just a small task to download video
    In video link you have to replace SS in place of www.
    Ex, Above link is shown like this,
    ssyoutube.com/zzzzzzzzzzz
    Thereafter you have to press enter and video can be downloaded
2) savetube.com
   Open this website, place your video link inside and video can be downloaded easily.