What does underground garage b 1 stand for?

B 1 floor refers to the underground floor, that is, the negative floor. The letter b is the abbreviation of the word basement, which means basement. B 1 refers to the basement, generally underground garage, food city or supermarket. Besides b 1, there are b2 and b3, which refer to the second and third floors respectively. In small shopping malls or residential buildings, b 1 is generally used as an underground garage or a large shopping mall, and b 1 is mostly set as a food city.