The car manufacturer will specify the service intervals. It will be at set intervals (At least once a year) or by travelled mileage.
There are 3 types of service, interim, full and major. There are always 3 levels in a tiered pricing structure.
So each level will include the lowest level plus some added extras.
An interim service. Intended for drivers with high mileage who travel 20,000 miles plus a year, for whom an annual service wouldn’t be sufficient. It includes an inspection of the car’s major components as well as an oil change and an oil filter change. The lubrication of all moving parts, fluid top-offs, and a check for fluid leaks should all take place too.
Drivers who travel less annually, a full service is often suggested every year or every 12,000 miles. It contains a greater selection of inspections and service replacement components.
The most thorough maintenance is a Major service, which is advised every 24 months or 24,000 miles. In addition to the aforementioned, brake fluid and cabin filters are also changed.

