ADU stands for "accessory dwelling unit". An ADU is a smaller residential dwelling unit - commonly referred to as a "granny flat", "secondary suite", "accessory apartment" - located on the same lot as a larger detached single-family home.
An assignment of contract is when the Buyer in a real estate transaction assigns their role to another Buyer in exchange for a fee. There's more to learn about assignable contracts at OfferMarket.
Buy, Rehab, Rent, Refinance. This is a highly effective methodology for high ROI rental property investing.
A real estate bird dog is someone to finds distressed properties and sellers of distressed properties for investors.