The second parameter of Object.create() defines property descriptors for the new object: 1) It allows setting own properties during object creation, 2) Uses the same property descriptor format as Object.defineProperties(), 3) Enables fine-grained control over property attributes (enumerable, writable, configurable), 4) Provides a way to create objects with non-default property attributes, 5) Combines prototype setting and property definition in one operation, 6) Creates more immutable or controlled objects when needed. This parameter is optional but powerful for controlling property behavior during object creation.