Currently Being ModeratedSep 25, 2013 1:17 PM (in response to Pilotleo)
iChat is an App that can login to the AIM, Jabber and iChat 6, the Yahoo services.
It can send text chats over those services to your Buddies.
With the Jabber and AIM logins you can also do Video chats.
These Chats are Peer-to-Peer and for the most part do not use the Servers that the Buddy is On. (i.e. you can log out of a Buddy list Server and continue a Video or Audio Only chat).
There is also a Bonjour Account.
this finds other Macs on your LAN and displays the User of that Mac in a Bonjour Buddy List.
This account can also do Audio And Video Chats.
Screen Sharing with an Audio Chat alongside can be done between your AIM or Jabber Buddies and the Bonjour Contacts.
iChat also include iChat Theatre which allows you to "Share" or rather display other apps (or documents of other apps) as the Video Feed.
You can show individual pics, a slide show, a movie file, Pages or Keynote/Powerpoint Presentations and so on.
You can also Chat up to 10 people including yourself in an Audio Only chat and up to 4 in a Video chat (does depend on your Internet speed)
Separate from Sharing/showing pics and files you can send them to your Buddies.
FaceTime is an app that comes from iOS
Originally it was iPhone to iPhone that were on wifi.
There is now a version for Macs.
It is still a one horse wonder.
It can only Video chat to one person at a time.
Bad Analogy coming up.
FaceTime = Capt Kirk on a planet with a communicator that can do Video
iChat = Potentially Federation Communications with Files and pics being sent while Video chats are taking place, with the potential to link to other people at the same time in the same conversation and the ability to remote control the other end in Screen Sharing.
Messages in Mountain Lion adds another account called iMessages.
Like FaceTime this comes from the iOS side of things.
It allows you to text chat with those iPhone Numbers and linked Apple IDs on iOS devices as well as people on Macs with the Messages application.
Like AIM is not that compatible with Jabber or Yahoo iMessages is it's own separate service run by Apple.
iMac 2.5Ghz 5i 2011 (Mountain Lion 10.8.4)
G4/1GhzDual MDD (Leopard 10.5.8)
MacBookPro 2Gb (Snow Leopard 10.6.8)
Mac OS X (10.6.8),
Couple of iPhones and an iPad
"Limit the Logs to the Bits above Binary Images." No, Seriously
Currently Being ModeratedSep 25, 2013 2:06 PM (in response to Pilotleo)