Be cautious buying vehicles with brands listed on the title, and vehicles being sold by a person other than the owner listed on the title.
Brands
A vehicle title is branded when a vehicle owner or insurer writes the value off as a total loss, typically because the cost to repair the vehicle exceeds the value of the vehicle.
A vehicle's brand(s) will be listed on the face of the title.
Transferring the vehicle to another party will not remove the brand - the authorities will brand every subsequent title issued for that vehicle until it has been destroyed.
Common brands include Totaled, Fire, Flood, and Salvaged (sometimes called Rebuilt or Reconstructed).
A vehicle with a Salvaged brand has been written off as a total loss, then rebuilt. Insurance companies will usually decline to write property damage (first party) insurance on Salvaged vehicles, as prior repairs may fail catastrophically in the event of an accident.
Vehicles with brands are eligible for liability (third-party) insurance, but are not eligible for first-party insurance.
It is illegal in all US states (and Washington, D.C.) for a dealer to sell a vehicle with a branded title without first disclosing the brand.
Title-Jumping
It is illegal in all 50 US states (and Washington, D.C.) for a person to sell a vehicle titled to another person unless the seller is a licensed auto dealer.
A person who sells you a vehicle that they do not own is guilty of title-jumping, a crime that carries penalties that include fines and/or jail time.
You are not committing a crime by buying a title-jumped vehicle, but it does create the conditions for a scam, for your exposure to open tickets or moving violations, and/or for unclear ownership when you sell the vehicle.