Onshore and offshore refer to domestic market and foreign market respectively. Among them, onshore RMB is RMB traded in Chinese mainland, and offshore RMB is RMB traded outside Chinese mainland. There is a difference between onshore and offshore. The biggest difference between them is whether you handle business in Chinese mainland or outside Chinese mainland.
For example, if you register a Hong Kong company or an overseas company, but do not operate in Hong Kong or overseas, it is an offshore company. An account opened in a domestic bank is called offshore account, and an account opened in Hongkong or overseas is called a local account. On the contrary, a registered company operating in Hong Kong or overseas is onshore, so the account he opens must be a local account.