A system cannot mature until it is tested in various scenarios. These scenarios are usually based on the experience of domain experts or existing production environments. There is always a chance that a system can crash in a production environment, even when the system is called a perfect system. For web applications, the conditions are even more critical due to performance glitches, bad user experience, and so on. A system should be put through a process or series of development principles to tackle these kinds of issues. Simply put, we must test the system. Testing is a process that ensures the quality of a system.
In other words, quality assurance, or testing, is a way to assess a system from different aspects. This process is also useful when a system requires testing to identify erroneous code, or if we want to assess its business compliance.
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