Instant Messaging

Instant-Messaging falls under the umbrella term online Chat since it is also text-based communication done in real-time, but is distinct in that it is based on clients that facilitate connections between specified known users (often using contact list, buddy list, or friend list), whereas online 'chat' also includes web-based applications that allow communication between (often anonymous) users in a multi-user environment.

Instant messaging (IM) is a set of technologies used for text-based communication between two or more participants over the Internet. Of importance is that online chat and instant messaging differs from other technologies such as email due to the perceived synchronicity of the communications by the users –chat happens in real-time. Some systems permit messages to be sent to users not then 'logged on' (offline messages), thus removing some differences between IM and email (often done by sending the message to the associated email account).

It is usually possible to save a text conversation for later reference. Instant messages are often logged in a local message history, making it similar to the persistent nature of emails.

IM allows effective and efficient communication, allowing immediate receipt of acknowledgment or reply. In many cases, instant messaging includes added features which can make it even more popular. For example, users may see each other via webcams, or talk directly for free over the Internet using a microphone and headphones or loudspeakers. Such Instant-Messaging systems are close to video-conferencing systems. Many client programs also allow file transfers, although they are usually limited in the permissible file-size.

Typical Instant-Messaging Client Programs are:

• ICQ
• MSN-Messenger
• Yahoo!-Messenger
• Skype

Sometimes E-Mail-Providers offer Instant-Messaging ability in their webpages, which can be used in a web browser with no need to download and install the IM client (Examples: Gmail, Yahoo, Hotmail)

Advantages:

• synchronous communication: quick and efficient way of communicating as answers are received right away
• text-based:
• no webcam and headset is required
• good if internet connection is slow as it doesn't require huge amounts of data to be exchanged
• specified users

Disadvantages:

• synchronous communication: participants have to be online at the same time
  
• text-based: not all levels of communication are transmitted (emoctions  are only a poor alternative)