Software testing is an essential part of the software development process, aimed at evaluating the functionality of a software application with an intent to find whether the developed software met the specified requirements or not.

So, basically we just want to find out: does it do what it's supposed to do?

Software testing involves running (or what we call executing) a program or app with the aim of identifying any software bugs, errors or defects. Software testing helps make sure that the application performs as expected in a range of predictable and less predictable conditions, making it a crucial aspect of what's known as 'quality assurance' (QA).

Validation, on the other hand, is the process of evaluating software during or at the end of the development process to determine whether it satisfies the specified requirements. It ensures that the product meets the customers needs, and that the specifications were correct in the first place.

In essence, validation answers the question: did we build the right product?