The cron daemon reads the /etc/cronlog.conf configuration
file provided by the user to log the information. If a
configuration file has not been created, then the cron
daemon creates a log of its activities in the
/var/adm/cron/log file. The cron daemon reads the
configuration file when it is activated and when it receives
the hangup signal.

If the cron daemon is not able to create or open the
user-specified logfile, then it creates a log of its
activities in the /var/adm/cron/log file.

corntab is excels over at command.we can submit a job for a 
year together.it is not a daemon because daemon is a system 
process that is run on background .we can not kill the 
daemon process.but we can kill the contrab command.

crontab is the service which is responsible to run the 
schedule in linux.

cron is driven by a crontab, a configuration file that
specifies shell commands to run periodically on a given
schedule.

The cron daemon checks the crontab files to see when 
particular commands are scheduled to be executed. If 
commands are scheduled, then it executes them.