Verification vs Validation
Verification and validation are common words of English language and their meanings are also somewhat similar, however, their use in the industry, particularly software development assumes significance in the wake of correctness of the product. Also referred to as V & V, verification and validation are vital for the success of any software. V & V pertains to quality control in software development though these words can be used anywhere, in relation to anything or product.
For example, when you buy a product from the internet, you get a lot of assurances about the features of the product. How do you verify if all the praise and the features that the company is talking about are in fact correct? Well, you can do so by checking on the reviews of the product on the net or if you are lucky and one of your friends has used the product, you can verify all the features through him. However, you cannot know for sure if the features are there in the product until you get the product and use it yourself. It is only after having used the product that you can say that you have verified and also validated the features. Thus validation of a product is something that comes only after verification and it cannot be vice versa.
Verification is like going through a checklist before the product is out in the market while its actual validation takes place when customers buy and use it. If you buy software from the market, you are told about is pros and features and you can verify these features by looking at the document given to you along with the software. But you are not 100% sure until you take it home and install it on your computer. It is only when you run the software on your system that you are able to validate all the features.
Verification is the process of ensuring that the product delivers all the functionality that is promised to the end consumer. This is usually done with the help of reviews, checklists, walkthroughs and inspections. Validation is the process of ensuring that functionality, as promised by the company is in fact the intended behavior of the product. This can only be done through actual use of the product.