ABS refers to the securitization of non-mortgage retail loans.
Unterforen: Aircraft-Backed Securities, Auto Lease-Backed Securities, Auto Loan-Backed Securities, Credit Card-Backed Securities, Diversified Payment Rights-Backed Securities, Equipment-Backed Securities, Marketplace Lending-Backed Securities, Railcar-Backed Securities, Rate Reduction-Backed Securities, Residential Solar-Backed Securities, Royalty-Backed Securities, Shipping Container-Backed Securities, Single Family Rental-Backed Securities, Structured Settlement-Backed Securities, Student Loan-Backed Securities, Timeshare-Backed Securities, Triple Net Lease-Backed Securities, Whole Business-Backed Securities

MBS are asset-backed securities whose cash flows are backed by the principal and interest payments of a set of mortgage loans.
Unterforen: Commercial Mortgage-Backed Securities (CMBS), Residential Mortgage-Backed Securities (RMBS), Collateralized Mortgage Obligations (CMOs)

In CDO transactions, the debt securities issued by the SPV are backed by a diversified loan or bond portfolio. There is thus a basic difference between CDOs and ABS, the latter being homogeneous pools of assets such as mortgages or credit card receivables, in contrast to the diversified portfolios backing CDOs.
Unterforen: Collateralized Loan Obligations (CLOs), Collateralized Bond Obligations (CBOs)