This blog delves into the concepts of sharding, partitioning, and segments in distributed databases like Milvus. Sharding refers to horizontal data partitioning across multiple servers, enabling faster writing by utilizing distributed systems. Partitioning organizes data for efficient retrieval, optimizing targeted reads. Automatic partitioning is recommended as it minimizes errors and ensures optimal performance. Each shard and partition has segments of data, with growing and sealed segments being the smallest unit in Milvus for load balancing. The default segment size is 512 MB, but adjustments should only be made if there are large machine resources available.