First, a small disclaimer: No matter how you slice up conferencing solutions, the categories you use to group them are mutable and subject to instant revision. Combinations of various elements make some applications basically impossible to categorize. Depending on how you look at it mail lists are even a form of conferencing and so is email. Real-time versus asynchronous is even becoming blurred as text, audio and video merge in varying combinations.

That said and out of the way, lets look at some of the ways conferencing solutions are categorized.

1. Real-Time Conferencing. Real-time conferencing refers to synchronous communications such that the participants are concurrently virtually present and able to actively interact as if they were physically co-located. Some typical and common applications are instant messaging and interactive chat, participatory webinars, interactive webcasting, online interactive teleseminars.

Now these are primarily web-based, however the old-time telephone conference call is still widely used. Call-in teleseminars are also common. Today however, they are merging into web applications as VoIP services with gateways into landline telephone systems become widely available.

2. Video conferencing is generally considered separately because it is a far more bandwidth intensive activity. To achieve reasonably acceptable simultaneous live video and audio, you need serious bandwidth. And the more active participants involved the more serious the problem becomes. Internet chat services with webcams are one rather simple form of video conferencing that's quite popular for individual person-to-person links, but clearly not of sufficient quality to use for business purposes or for larger groups. Some video conferencing is one-way video with interactive audio. Others require high-speed networks or dedicated connections. High-end solutions may work well for large corporations because of the savings involved in reducing travel expenses and time lost from productive work.

3. Forums, message boards, bulletin boards and so forth. These are asynchronous forms of conferencing or discussion solutions. Even blogs and wikis may, at times fall into this category. Generally these are linear or threaded, topic centered meeting places with chronologically tagged sequential entries that make up a discussion. Some prefer the linear mode as being easier to use and follow while others insist that threaded tree-like structures often more scope and the ability to develop sub-topics integrated into the main topic. Whatever one