AM4 is a PGA CPU socket designed especially for all AMD processors with Zen, Zen+, Zen 2, Zen 3, and Excavator microarchitecture. Basically, if you want an AMD gaming build, you’ll need a motherboard with an AM4 socket.
Released in September 2016, it was designed to be a one-stop, universal socket for new processors, rendering previous formats, AM3+, FM2+, and FS1b redundant. Featuring support for both single and dual-channel DDR4 memory, it was able to compete with Intel’s advanced sockets.
There are currently three series of chipsets under the AM4 umbrella, with eight options in total, but for gaming, you’ll most likely only need to decide between two series. Typically found in high-end boards designed for ultra-low latency gaming, the X-Series is the premium option.
The B-Series is more of a consumer-friendly option, and due to their affordability, are the most popular choice for standard gaming builds.