Check_host_alive and check_ping

Whats the difference between check_host_alive command used to check hosts and Ping service which also uses check_ping plugin?
According to me there is no difference but i still see a lot of people use both the commands.
Any suggestions from anyone. Thanks.

Host commands are NOT run on a scheduled basis. YOu can have many service checks for a host, and yes, one of them is check_ping. Look at the definitions of the check commands check-host-alive and also checkping. YOu will see that both of them use the check_ping plugin, so the only difference would be HOW you define the command. Different options? packet size? etc?

Thanks for the reply.