Verizon Fios vs Optimum = Fiber Optic vs Cable. Fiber Optic Cable [1] The main difference between Verizon Fios and Cablevision is the technology underlying the service. Verizon Fios uses a fiber optic connection delivered directly to your home, where Cablevision uses old cable technology. This allows Verizon Fios to offer some of the fastest internet speeds in the country.