First off, the function keys are gone, replaced with a Touch Bar multi-touch display strip that provides instant access to tools and shortcuts. The shortcuts change depending on what software application is being used, and are also customizable.
The Touch Bar also features a Touch ID sensor for logging into the machine and authorizing Apple Pay payments. The Touch ID sensor required Apple to build a new chip, called the T1, to act as a secure enclave for the sensor.
On the outside, the MacBook Pro features an all-aluminum design (you current MacBook users are probably looking for the plastic on your laptop (keep looking, I won't spoil your fun), four Thunderbolt 3/USB-C ports, which along with a headphone jack, are all the connectivity you'll be getting.
The Thunderbolt 3 ports support 40-Gbps data transfer rate and can support two 5K displays and function as USB, DisplayPort 1.2, HDMI, or VGA ports with the appropriate dongle(so expect a lot of dongles in your future). When working as USB-C ports they offer 10 Gbps of data transfer.
There's also no MagSafe charging port, as this function too has been handed over to the Thunderbolt ports (you can use any port for charging).
The MacBook Pro also kitted out with a more responsive keyboard, with the keys being fitted with a second-generation butterfly mechanism, and a new Force Touch trackpad that's twice as big as the previous trackpad.
The MacBook Pros also feature improved speakers and a redesigned thermal architecture.