A locale is a location-based language setting that determines which conversational settings and strings to display.
The user specifies their locale using settings on their device. They may change this setting whenever they wish, including during a conversation with a Business Messages agent.
A Business Messages agent or location can also specify which locales they support and set a default locale that they usually communicate in.
Business Messages compares the user's locale and the agent's locale to determine the best match, called the resolved locale. Business Messages uses the resolved locale to select which conversational settings and strings to display. It's best practice for agents to communicate in the resolved locale to maintain a consistent user experience.