Accelerators accelerate the speed of your business. In most cases an existing business or an idea. The programs are short and intense. They help you hone your idea and build it out.
What is Incubator?
Whereas incubators incubate your early pre-product idea, help you make a prototype, and further make a product out of it. The engagement is longer than an accelerator.
Here's a list of Incubators & Accelerators by cities.