...It provides encoding and decoding capabilities so JavaScript environments like Node.js and browsers can serialize rich data structures (including types not native to JSON) into the compact, efficient BSON binary representation used by MongoDB drivers and servers. Value types such as ObjectId, Binary, UTC datetime, Decimal128, and Long are provided as first-class objects, enabling precise representation of data that would otherwise be lossy or awkward in plain JSON. js-bson is designed for performance, with optimized algorithms for reading and writing binary data, minimizing overhead in database operations. Because it’s a foundational building block for MongoDB drivers in JavaScript, the library ensures consistency and compatibility between client applications and the MongoDB server.