Integration tests will test groups of software components as they work with each other. While unit tests can help validate the functionality of a block on code in isolation, integration tests help test blocks of code as they interact with one another. Integration tests are useful because they can help catch different types of issues that arise when software components interact.
While unit tests may be run in a developer's workstation, integration tests are usually run when code is checked into source control. A CI server will check out the code, perform build steps, and then follow with any smoke tests and then run unit tests and then integration tests.
Since integration tests are a higher level of abstraction and test ...
