A more thorough explanation:

A correspondent is someone who writes letters or reports on events for the media. It can also refer to a financial institution that provides services in a market where another institution does not have direct access.

• A journalist reporting on the war in Syria is a correspondent for a news organization.
• A bank in the United States may use a correspondent bank in Japan to make transactions in Japanese yen.

These examples illustrate how a correspondent can be someone who provides information or services from a remote location. In the case of a journalist, they are reporting on events from a different location than their audience. In the case of a bank, they are using another institution to access a market they do not have direct access to.