Issues may include the security of the web application, the basic functionality of the site, its accessibility to disabled and fully able users, its ability to adapt to the multitude of desktops, devices, and operating systems, as well as readiness for expected traffic and number of users and the ability to survive a massive spike in user traffic, both of which are related to load testing.
By doing so, the tool is useful to check for bottleneck and performance leakage in the website or web application being tested.
Web security testing tells us whether Web-based applications requirements are met when they are subjected to malicious input data.
[1] There is a web application security testing plug-in collection for FireFox[2] An application programming interface API exposes services to other software components, which can query the API.
The API implementation is in charge of computing the service and returning the result to the component that send the query.