What is difference between starting Instance with -T3608 and with -f?

I simulated a corruption of model database on test environment just for learning purposes. While reading others blogs and articles about it I stuck on the question, what is difference between starting SQL Server Service with undocumented -T3608 and -f flags? When I tried to start service with -f, then got error message and service didn't start. However, in case of -T3608, it started smoothly. For -T3608 flag, I read that, -T3608 starts all databases without performing recovery and -f starts instance with minimal configurations. What is minimal configuration, I can't find info about it.