Curb weight
The car's weight ready to drive: fluids and standard equipment included, occupants and cargo not. Definitions vary by standard.
Curb weight is what the car weighs sitting at the curb ready to go: fluids in, standard equipment fitted, but no people or luggage aboard. It is the baseline weight figure on a spec sheet, and the difference between it and the GVWR is the payload you are allowed to add.
The trap is that "ready to go" is defined differently across standards. The US federal definition counts standard equipment plus the maximum capacity of fuel, oil, and coolant. GOV.UK lists two separate UK terms: "unladen weight", which does not include fuel or, in an electric vehicle, the battery, and "mass in running order", which for cars includes the driver, essential fluids, and a full tank of fuel. So two sources can legitimately disagree about the same car, and CarPairly records the manufacturer's stated figure with its source noted.
Batteries add mass, so an EV can list a higher curb weight than a comparable gas car. Payload arithmetic and towing capacity both depend on the weight figures, so compare the numbers for the exact models you are considering.
Differs by market
British English spells it "kerb weight", and GOV.UK uses the terms "unladen weight" and "mass in running order". The US regulation counts standard equipment and the maximum capacity of fuel, oil, and coolant, while UK "mass in running order" for cars includes the driver and a full tank of fuel. Small cross-source differences are normal. CarPairly shows kilograms or pounds according to the viewer's market.