A payment request is an instrument to collect money for a specific purpose and amount from one or many customers. A payment request ID is generated when a new payment request is created. It is a random string of 32 characters and will be simlar to 4ce986c9d9614224bd044d1331c531ff
A payment ID is generated when a customer makes an actual payment against a payment request. There could be multiple payments (and hence multiple payment IDs) against a single payment request. A payment ID is a 20 character string prefixed with MOJO, for example MOJO6c09000J31957837