Not exactly the same.

Annealing: lowers hardness, relieves internal stress, improves machinability; the temperature is relatively lower, and the cooling method depends on the purpose.

Solution treatment: after fully dissolving the alloying elements into austenite, rapid cooling (water quenching) is applied; the purpose is to restore corrosion resistance and ductility, and the temperature is higher (e.g., about 1050-1100°C for 304).

What this means for purchasing: when corrosion resistance needs to be restored after welding or cold working, solution treatment rather than ordinary annealing should be specified; check the heat-treatment condition clearly on the mill certificate.