sid

Hi all, i was wondering, there is alot of talk about realtime and up to the minute data but what i dont understand is this.

Twitter for example is considered realtime because the information is up to the minute and discussing topics that are now.

However with twitter if you dont refresh your page the information will be old. In friendfeed for example, if there is some new information, it will automatically show and appear as it is created.

My question then is, what is realtime, is it the ability for the information to appear on the website as it is created or is it more about the data being about realtime events and topics ?

My next question is, if it is about the page being updated and refreshed in realtime like friendfeed and gmail, how do you implement that short of polling. Doing it with polling is very easy but also very inefficient, is there actually something out there that allows this realtime update of information without polling or is this how friendfeed and gmail do it ?

Thanks alot guys