Suppose you are watching an interesting 10 min video on YouTube and you would like to share it with a friend. An important part in the video starts at 3rd minute and 33rd second. It was not possible untill recently to start the video at a specified time. The user had to wait till the 3rd minute and 33rd second then watch the video. But now with a small change in the URL [eg.http://www.youtube.com/watch?v=qazwsx] you can change it to
http://www.youtube.com/watch?v=qazwsx#t=3m33s
and that will start the video at 6 min 30 sec. This is a very small tweak but very very useful.
Let’s examine closely what extra # we typed does
t= time, m=minutes, s=seconds. So if I type #t=3m33s it means 3rd minute and 33rd second; the video will start exactly at the time specified.