MacBook Pro with Retina Display
To slim down the Retina-equipped MacBook Pro to near-Air dimensions, Apple got rid of the DVD drive and the traditional spinning hard drive. Instead, it uses flash memory for storage. The model also lacks an Ethernet port for Internet connections. Those who want to go online have to use Wi-Fi or buy an Ethernet adapter that goes into the laptop's "Thunderbolt" port. The Air models also lack Ethernet ports, DVD drives and spinning hard drives.