Step-by-step explanation:
Chatter is a social networking platform that allows business employees, partners and customers to produce and communicate in a secure social environment.
To post a message on Chatter, the developer should do the following :
• Using Workflow Rule and use the "Post to Chatter" action when records meets the criteria.
• Using streaming API to post in Chatter.
• Using ConnectApi from Scheduled Apex.
• Using a Process Builder to post in Chatter which meets the required criteria.