Widely used in databases. 

Sometimes useful in microservices(only a few services in the system. _
It has 2 phases:-

1. Prepare Phase

2. Commit Phase. 

MIcroservices are asked to prepare for changes

Create a record in database adn set its status field or column to 0(NOT Stable)

Microservices are asked to make final and actual changes.

Set the value of actual field column as 1

A coordinator microservice is needed in order to maintain lifecycle