"本家"指一个家族里最早、最重要的那一支，也可以说是某个东西最早的、真正的来源。

"本家" refers to the earliest and most important branch of a family, or the original source of something.

我们常用它来说某样东西是"正宗的"、原来的那一个。

We often use it to say that something is the "authentic" or original one.