According to the inquiry, we know that Youjia and Didi Daijia are two different driving services, and there are some differences between them:

1. Service mode: Priority driving is usually a location-based driving service. Users can submit driving requirements through the application and then wait for nearby drivers to take orders. Didi Daidai is a driving service provided through Didi Chuxing platform, and users can make an appointment for driving service in Didi Chuxing application.

2. Cost calculation: The cost of ex gratia driving is usually calculated according to the distance and time, while the cost of Didi driving is calculated according to the service type and mileage.