about RSS Feeds

[nunchukz]

Hi,

i am new to feeds and just read up how to create rss feeds.
however i still don't understand about the updating of feeds.

for example.. i've created this feed domain.com/domainfeed.xml
feed readers will read the file and bring the info to the subscribers. or rather subscribers will read tt file for feeds.

do i update this same file when my site got a new update? do is there other way to do it?
and how do i update it?

reg,