the relationship among brand, series and model.

brand is the name, trademark and code name, in fact, it is just for everyone to remember.

series is the general category of goods. We are familiar with many brands such as Adidas, which includes clothing series, shoes series, hats series and backpacks series. There are also sub-categories under these categories, as well as electronic brands such as Samsung, televisions, computers, mobile phones, refrigerators and air conditioners, and so on.

models related to electricity are products with specific categories, such as Samsung I91 GALAXY SII and I99.