An Access Token allows you to get the authorized information on behalf of your user.
An Access Token represents a user or admin who has authorized your client. This Access Token should be used in every API call. The Access Token is only valid for a given amount of time. Once an Access Token is expired it can be refreshed by sending the refresh token to the same endpoint. Access tokens can only be refreshed for 14 days. After 14 days, the user must be authenticated with its credentials again.
Remember to keep your tokens secret!