Yes, all the boat rental agencies offer this service. You can book simply a private transfer or a combination service that pairs a transfer with a tour of Capri or the Amalfi Coast. From April through October, there is also a ferry service between Capri and Positano.
https://www.positano.com/en/ferry-schedule Ferry schedule Capri - Positano]

If you are staying on Capri, the best way to visit the Amalfi Coast is by boat tour so you can combine a day at sea with stops in Amalfi and Positano and enjoy the view of the coast from the sea. If you are staying in both Capri and the Amalfi Coast, book your boat tour on the day you are travelling from the island to the coast or vice versa, so you can use your day at sea as a transfer service, as well.

It takes less than an hour by boat.

Yes, boat tours from Capri to the coast include a stop at Positano and Amalfi. From Amalfi, you can take the bus or taxi up the cliffside to Ravello.