The Amazon S3 Express One Zone storage class is purpose-built to deliver the fastest cloud object storage for performance-critical applications that demand consistent single-digit millisecond request latency. S3 Express One Zone can improve data access speeds by 10x and reduce request costs by 50% compared to S3 Standard and scales to process millions of requests per minute for your most frequently accessed datasets. It enables workloads such as machine learning training, interactive analytics, and media content creation to achieve single-digit millisecond data access speed with high durability and availability.
Source:: Amazon AWS