Usability testing is one of the most common techniques for evaluating how a product performs from a human centered perspective. By observing real users attempting a task you can gain insights to problem areas of your product and gather user feedback. If a product is considered difficult to use, it creates obstacles for users trying to complete their goals and can have a negative impact on the business and on the overall user experience.
A key aspect of this technique is that it focuses on the user's actions, and for that reason, helps reduce biases and assumptions and also check if the design solves the user's real problems while fulfilling the business goals.
There are different ways to apply usability tests and also different moments when you can run it during a project life cycle. Some benefits are: