[CQ-Contest] How is Log Checking actually done?

[David Jones]

Pardon if this seems like too simple a question, but are there sources of
information as to how log checking is actually accomplished?
The Cabrillo thread actually prompted my thought.

Based on submitting in that format, is there a "magical" way to merge every
log and then determine who has contacted who, and which are and are not
valid?  In other words, have the machines check logs, instead of humans (the
old fashioned way)?

David VE3STT
ve3stt at rac.ca