What is an existing house? What is an auction house? What is commercial housing?

Hello, the existing house refers to the commercial house that can be moved in as soon as it is bought, that is, property right card where the developer has completed the sale of the commercial house. The buyer can move in and obtain the property right certificate after signing the commercial house sales contract with the developer. Auction house refers to the house under construction, which has not been completed and cannot be delivered for use. From the beginning of obtaining the pre-sale permit of commercial housing to the end of obtaining the property right certificate, the commercial housing in this period is called forward housing, and the purchaser should sign a pre-sale contract when purchasing commercial housing at this stage.