Your Internet Consultant - The FAQs of Life Online
To understand what Usenet is, you need some idea of how it works. First, there is no central Usenet authority, unlike online services such as CompuServe or AppleLink. All systems participating in the Usenet act like super copying machines, in that an article that you send to the Usenet (this is commonly known as a posting) is saved on your local machine and an exact duplicate is sent to a group of other machines that your system "talks" to directly. Each of these machines keeps its copy and forwards duplicates to the machines that they talk with, and so on, until your words might well have been duplicated tens of thousands of times!
The great thing about this strategy for distributing postings is that at any given time your local system will have all the relevant postings in the groups that you're interested in reading, with more coming in hourly (if not more frequently!) Because they're all on your local computer, you can usually read the group or groups that interest you quickly, certainly without any lag as a central system doles out individual items. Indeed, many people actually set up their home computer systems to have the Usenet articles sent to them automatically. Then they can use Mac or Windows newsreading software to peruse the new information at their leisure.