What are a Message function and its type?

It is a type of function, using this we can send messages to Workstation using synon/2e. The
message function has
a. Send error message (using this we can pass a error message to the message queue)
b. Send information message (using this we can pass a information message to the message
queue)
c. Send completion message (when a job is completed this message will appear)
d. Send status message (it gives information about the long running program’s status to the
message queue)
e. Retrieve message (it retrieve a message from message file to the function, using this you can
concat even 2 database fields)
f. Execute message (Request message to be executed by the calling function)