According to Wikipedia, Android Go is a tailored distribution for low-end devices was revealed for Android Oreo; it is intended for devices with 1GB RAM or less. This mode has platform optimizations designed to reduce mobile data usage (including enabling Data saver mode by default) and a special suit of Google Mobile Services designed to be less resources and bandwidth intensive.
Android Go is a pretty efficient budget OS and more and more companies have started manufacturing devices on the same. Samsung SM-J260G has been listed at the famous listing site, Geekbench. According to the listing, the device has 1GB RAM and runs on Android 8.1 Oreo out-of-the-box. It will run on the special Android Oreo (Go Edition) and is expected to be launched as Samsung Galaxy J2 Core.
Under the hood of Samsung Galaxy J2 Core would be ‘universal7570_go’ chipset. This chipset is expected to be a specially optimized version of Exynos 7570 chipset for Android Go OS. It will clock at a speed of 1.43GHz.
Besides Samsung, Alcatel, Lava and Nakia already have Android Go devices in the market. You may check them out to get a clearer idea of the devices, how they work, etc. This, being just a listing, should be taken with a pinch of salt.