An accelerator is an organization that helps early-stage entrepreneurs to refine an idea while also providing access to resources; an incubator is an organization that provides tailored support for existing startups that have already built a successful product or service.

The definitions given in the statement are actually reversed. An accelerator is an organization that provides tailored support for existing startups that have already built a successful product or service, while an incubator is an organization that helps early-stage entrepreneurs to refine an idea while also providing access to resources.