Hi,
CAIPS is short for 'Computer Assisted Immigration Processing System'. It is the computer system historically used by Citizenship & Immigration Canada to process visa applications, and holds all the information on the current status of every immigration application being processed by overseas offices (i.e. those outside of Canada), other than new applications at offices which have switched to using the 'GCMS' system.
Please follow the link for more details. Thanks
http://www.canadavisa.com/canada-immigration-discussion-board/-t72568.0.html