The most widespread means of group communication on the networks are the well-established tools, mailing lists and Usenet News . These provide a highly flexible and popular means of network communication for interest groups. A feature of their flexibility is that simultaneous connection between message sender and recipients isn't necessary. This type of communication is known as 'asychronous' communication. The complementary mode of 'synchronous' communication is employed by a whole swathe of tools which enable the people involved to connect simultaneously and communicate interactively with each other.
Collaboration tools employ both methods to facilitate the business of working together online.