Definition: text messaging vs. instant messaging

Text messaging and instant messaging are similar because they are both used to send text messages. However, text messaging ("texting") uses the cellular phone service, whereas instant messaging employs the Internet. Text messages are typically limited to 160 characters, but instant messages can be longer.

After a text message is transmitted, the session is essentially ended even though the recipient can respond and keep the back-and-forth going all day. When an instant messaging session is started, it typically remains connected until ended by one of the parties. Both text messaging and instant messaging are often called just plain "messaging." See text messaging, instant messaging, SMS and chat.

Text Messages Can Initiate Things

Another difference is that texting can activate some function by sending a word or two to an organization that has been assigned a coded destination address (see short code).