How to start cron service using Linux Command?

Cron

Cron is a time-based job scheduler used in Unix-like computer operating systems. It is most suitable for scheduling repetitive tasks. A command to an operating system or server for a job can be executed at a specified time.

The command to start cron is crond start

To start the cron service, use the following command 

# /etc/init.d/crond start

OR RHEL/CentOS 5.x/6.x user:

# service crond start

OR RHEL/Centos Linux 7.x user:

# systemctl start crond.service