I know most of you still struggling with the topic. Don't worry. Just relax and seat yourself. From today you will be confident that what the topic actually is. Let's see a scenario first:
We are to build a Bicycle. So we are building it step by step. Suppose we are building the Body frame first. Then we are checking that it is actually a body frame or something else. Then again we are setting tires, and bell, and then checking whether we are going in the right direction or not.
After completing the whole process we are checking that actually we have made a bicycle or anything else.
See the picture below;
The second and third process is called "Verification" and the last process is "Validation".
Verification: When we are to build a product and at the building time we are severally checking whether we are building the right product or not.
Validation: When our product is completed and ready to launch in the market then we check whether what we have done with our product is right or wrong.
So let me know if you get it clear or not. Any kind of suggestion is highly appreciable. Keep learning.