The Basics — CAP Theorem Explained

CAP theorem or Brewers theorem (named after computer scientist Eric Brewer) often gets mentioned in combination with distributed systems.

The theorem states that it is impossible for a distributed system to have more than two of the following three properties:

  • Consistency
  • High Availability
  • Partition tolerance

Distributed system is a collection of computers that are connected through a network and appear as a single computer.

What is consistency?