Travis CI is a hosted continuous integration service used to build and test software projects hosted on GitHub and Bitbucket.
We can select the repositories and their branches, whose changes we want travis to detect and make it deployment ready.
As soon as changes detected by Travis, it runs some tests on the new code.
If tests were successful, it integrates those changes on the hosting platforms like AWS.
Thus it removes the manual integration step; new features get automatically deployed into production if the code passed test cases of Travis.