Original link: Understanding Microservices: Core Concepts and Benefits / Milan Jovanovic blog.
A lot has been written about microservices. A good part of it is "religious cult style" praise. This one is actually pretty good both at explaing what, why and why not.
For those that want more then I can recommmend the book "Software Architecture: The Hard Parts".
Or for those that like my ramblings Architecture - service definition.