MBS vs MPS

Hi there, Can someone please help me differentiate between: a) Mortgage Backed securities b) Mortgage Passthrough securities Thanks!

MBS is a security that has mortgage cashflows as the collateral. MBS can be either a mortgage passthrough security or a collateralised morgage obligation. MPS- teh mortgage cash flows recd froma mortgage loan are given to MPS owners in proportion of their holding. CMO- tranches of CMO exist with the superior tranches receiving the payment first.

That’s probably right for the exam, but you might want to be a little flexible on that. I wouldn’t worry much about this.