Difference between Karma and Mocha

Imagine the following scenario:

• Write your own test suites with Mocha

• Use Karma to run programmatically your Mocha tests cross-browser and
  cross-devices

• More, integrate Karma with your Jasmine existing environment

• Even more, integrate Karma in your Continuous Integration cycle

• Use a million Karma plugin to check coverage, complexity, framework
  stuff, etc…

The power of Karma is that it can spawn real browsers – such Chrome or Firefox – to effectively test your code with them.

With Mocha you can run it in a NodeJS environment or in a webpage.