Avro is a data serialization system that helps in storing and exchanging data efficiently. It is part of the Apache Hadoop ecosystem and is designed to work with big data applications. Avro uses a compact binary format, which makes it fast and space-efficient. It also supports rich data structures, allowing users to define complex data types easily. One of the key features of Avro is its schema evolution capability. This means that as data structures change over time, Avro can still read old data without any issues. This flexibility makes it a popular choice for developers working with large datasets in data processing and analytics environments.