The prototype property of AsyncGeneratorFunction.prototype is shared by all async generator functions. Its value is AsyncGenerator.prototype. Each async generator function created with the async function* syntax or the AsyncGeneratorFunction() constructor also has its own prototype property, whose prototype is AsyncGeneratorFunction.prototype.prototype. When the async generator function is called, its prototype property becomes the prototype of the returned async generator object.

The prototype property of GeneratorFunction.prototype is shared by all generator functions. Its value is Generator.prototype. Each generator function created with the function* syntax or the GeneratorFunction() constructor also has its own prototype property, whose prototype is GeneratorFunction.prototype.prototype. When the generator function is called, its prototype property becomes the prototype of the returned generator object.