Reliability testing: Reliability Testing is about exercising an application so that failures are discovered and removed before the system is deployed. The purpose of reliability testing is to determine product reliability, and to determine whether the software meets the customer’s reliability requirements.
Usability testing: In usability testing basically the testers tests the ease with which the user interfaces can be used. It tests that whether the application or the product built is user-friendly or not.
Efficiency testing: Efficiency testing test the amount of code and testing resources required by a program to perform a particular function. Software Test Efficiency is number of test cases executed divided by unit of time (generally per hour).