Ryzen and Zen are the same, whereas Zen is the architecture and Ryzen is the product name of the AMD consumer-based CPU's. So Ryzen CPU's are based on the Zen architecture, Zen 1 architecture is used for the Ryzen 1000 series CPU's(Ryzen 1600X et), Zen+ is used for the Ryzen 2000 series CPU's(2600X etc.). Zen 2 architecture is used for the Ryzen 3000 series(3600X etc.) Zen 3 architecture is used for the Ryzen 5000 series(5600X etc).