System testing, also known as system-level testing, involves evaluating how the various components of an application interact in a fully integrated system. It is carried out on the entire system under either functional or design requirements.
It helps you find flaws, gaps, or needs that are lacking in the software application's overall functionality. It validates the design, behavior, and customer expectations of the system. Software Requirements Specification (SRS) is necessary to function the system outside the specified restrictions.