On most domestic flights, business and first class are essentially the same. In fact, most airlines simply call it first class domestically.
When it comes to international flights, it depends on the flight and carrier. Some airlines have replaced first class with business class entirely. On others, there is both first and business, with first offering an even more upscale experience. Imagine all the perks of business, but perhaps instead of simply lie-flat seats in business, first class has lie-flat seats that can become double beds, ensconced within a private suite that’s practically a bedroom. These suites will cost several times more than a business ticket, but the standard of service will be unmatched.
First class passengers always come, well first, when it comes to boarding, in-flight service, and perks. On luxe carriers like Emirates, first class might also include bathrooms with showers, or private transportation to the airport. There’s also fewer seats but plenty of flight attendants, so you’ll want for nothing.
Read more about the difference between first class and business class.