On the front of the phone you have a 5.2-inch, 1440×720 (309PPI) LCD. The whole front is wrapped in Gorilla Glass 3, and while it's not exactly a slim-bezel design, HMD is still equipping the device with an extra-tall 18:9 aspect ratio display. For the body of the phone you get an aluminum chassis, which is only exposed on the sides, and a plastic back.
Surprisingly, the Nokia 3.1 has a MediaTek 6750 SoC instead of the usual Qualcomm chip. This is a 28nm SoC with eight Cortex A53 cores (four clocked at 1.5GHz and four at 1.0GHz) which gives it a decent speed advantage over, say, the Snapdragon 427 in the $184 Moto E5 Play or $199 Moto G6 Play, which only have four Cortex A53 cores. The baseline Nokia 3.1 also comes with 2GB or RAM, 16GB of storage, and a 2990 mAh battery. There's a micro-USB port, a microSD slot, and a headphone jack.
At this price point, there are going to be some compromises; in this case, you miss out on a fingerprint reader and NFC. International versions of the 3.1 have NFC, but the US version doesn't. Speaking of US limitations, it doesn't seem like the 3GB RAM/32GB storage variant will come to the US, either.
Nokia's update policy is basically unheard of at this price point—it's offering monthly security updates for three years and major OS updates for two years, the same deal you'd get with a good Android flagship. Most other OEMs would take your money and run. And since it's an Android One phone, you get pure stock Android 8.0 without any skins or crapware.
Usually, the only decent US phones in this price range are found in Motorola's lineup, but the Nokia 3.1 is cheaper than anything from Motorola and should be a bit faster. Motorola is offering bigger batteries, while Nokia has a better update program.