Stagnation point is a point in which the speed is zero, and all of the kinetic energy isentropically has been transformed to internal energy and has been added to static enthalpy. Stagnation Temperature is the temperature of such a point and in this point it is equal to the total temperature.
It is worth mentioning that stagnation temperature is different from static temperature.
For more details I have attached a useful file about compressible flow.