YugabyteDB is a transactional, high performance, geo-distributed operational database that converges multiple NoSQL and SQL interfaces into an unified solution. The modular architecture allows for the same transactional guarantees irrespective of the API used, with most differences limited to the query layer. A YugabyteDB cluster is known as a universe, composed of nodes running YB Tablet Server processes, which handle data storage, replication, and querying tasks, as well as YB Master processes responsible for storing metadata and coordinating actions. Write operations travel through the database in seven steps, involving query language processing, forwarding to the tablet leader, preparing the batch for replication, Raft replication, applying the update to the storage engine, responding to the client, and finally applying the update to the followers' storage engines. Background operations include compactions, flushes, load balancing, and tuning read consistency levels. The common storage engine is used across multiple data models, access patterns, and consistency levels, allowing for operational simplicity with features such as auto sharding, auto load balancing, zero downtime infrastructure portability, and tunable read consistency.