Software testing is a process of executing a program or application with the intent of finding the software bugs. It can also be stated as the process of validating and verifying that a software program or application or product: Meets the business and technical requirements that guided it's design and development.
Management in businesses and organizations is the function that coordinates the efforts of people to accomplish goals and objectives by using available resources efficiently and effectively.
The mobile operating system for Apple mobile products. Android and iOS are direct rivals. Personally, I believe Android is better for more advanced users, and iOS is for users who want a more simpleminded experience.