email, newsgroups and chat
These are the messaging protocols that allow users to communicate both asynchronously (sender and receiver aren't required to both be connected to the Internet at the same time; e.g. email) and synchronously (as with chatting in "real time").
This method of Internet communication has become the standard. A main computer acts as a "post office" by sending and receiving mail for those who have accounts. This mail can be retrieved through any number of email software applications (MS Outlook, Eudora, etc.) or from Web based email accounts (Yahoo, Hotmail). Email is an example of asynchronous Internet communication.
Email also provides the ability to access email lists. You can subscribe to an email list covering any number of topics or interests and will receive messages posted by other subscribers. Email communities evolve from interaction between subscribers who have similar interests or obsessions.
Usenet is something like a bulletin board or an email list without the subscription. Anyone can post a message to or browse through a Usenet newsgroup. Usenet messages are retained on the serving computer only for a predetermined length of time and then are automatically deleted, whereas email list messages are retained on the serving computer until the account holder downloads them. Many email applications, as well as Web browsers, allow you to set up Usenet newsgroup accounts.
IRC (Internet Relay Chat)
This protocol allows for synchronous communication: users on different computers anywhere in the world can communicate in "real time" or simultaneously. You can instantly see a response to a typed message by several people at the same time. This protocol requires a special software application that can be downloaded from the Web, generally for free.
The following are external links and will open in pop-up windows: