Theorem of CAP

The CAP Theorem states that in a distributed system—like a large, complex database—it’s impossible to simultaneously guarantee three things: Consistency (all users see the same data at the same time), Availability (the system always responds to requests), and Partition Tolerance (the system continues to operate despite network failures). During network splits, you must choose to either stay consistent or stay available, but not both. Essentially, you can't have it all at once; the design depends on which properties are most critical for the specific application.