Three types of service protection API limit errors that can be returned:
1. Number of requests
This limit counts the total number of requests during the preceding 300 second period.
2. Execution time
This limit tracks the combined execution time of incoming requests during the preceding 300 second period.
3. Concurrent requests
This limit tracks the number of concurrent requests.
Reference:
https://docs.microsoft.com/en-us/powerapps/developer/data-platform/api-limits