How to download videos from you tube?

Just search for keepvid in Google search.. ANd open Keepvid site. Just paste any youtube URL which you want to download and it will give you downloading link.. This is the easiest method so far I came to know. No need of any software.

You can do it if you have a real player in your computer as well other than all other methods mentioned by other members

There are many ways you can download.

1. You can install You tube downloader software on your desktop and initiate downloads by specifying the URL in the path for download

YouTube Downloader is software that allows you to download videos from YouTube, Facebook, Google Video, Yahoo Video, and many others and convert them to other video formats.

2. You can install the download helper add-on which automatically activates on playing a video and provides download options. (Specific to Firefox browser)

Hai Rashmi , 

Here are some methods to download videos from youtube. 

METHOD 1: If you have Realplayer installer on your system, then just click on the download via Realplayer. This is easy method. 

METHOD 2: There is a site called online.movavi.com 
Just have a free account here. You can just add the url of the video here and get the video downloaded from here. This site also provides the videos that can be converted into your preferred formats. 

The above stated methods are very helpful and were experimented by me. These would be very useful for you. 

thru IDM

There are a lot of websites which can help download youtube videos.

Orbit YouTube downloader is free and can download video from YouTube easily with great speed. Orbit Downloader can not only download video from YouTube but can be used to download video all social video and music sites like YouTube, Dailymotion, Myspace, Pandora...etc.
Download from here :
http://download.cnet.com/Orbit-Downloader/3000-2071_4-10600926.html