ACID compliance` refers to a set of principles that ensure database transactions are processed reliably, providing reliability, correctness, and essential features like atomicity, consistency, isolation, and durability. These four strong guarantees provide the foundation for ensuring that database operations succeed or fail in reliable ways, maintaining a consistent state at all times regardless of software errors, hardware issues, or power failures. The elements of ACID compliance, including atomicity, consistency, isolation, and durability, work together to ensure data integrity and prevent anomalies like immortal writes, stale reads, and causal reverse problems. Maintaining these guarantees is complicated by modern systems that need to store data reliably across multiple servers, often in distributed geographically, which poses significant challenges. However, some vendors like Fauna offer solutions that provide strictly serializable, externally consistent transactions without the usual limitations or headaches, making it possible to achieve ACID compliance with distributed transactions and easily scalable database systems.