区别就是两者都是名词，表书店时意思是一样的，可以互换，但具体的不同如下

bookshop中文意思是n. 书店(相对小点)

Guanghua Bookshop as a stand-alone bookshop may face a loss, because profits from selling print books are slim and rents in central London are high.

bookstore中文意思是书店(相对大点)

He stopped at the bookstore.