Fresh vs. Old Egg - How to spot difference between fresh and old egg.

Durring the food preparations where we are using fresh eggs if it's frying, poaching or baking, sometimes we can see that our eggs whites are really wet and sprawl across the frying pan, or our cake mix become wetter than should be? 

Or sometimes we can see that our eggs whites are firm and they are keeping great shape during the cooking/frying, and they are less wetter?. There is a simple answer to that!

If our eggs are nice firm and they are keeping great shape, it's means that they are fresh eggs and they from young healthy chickens, but if our eggs whites are wet and runny, this means that our eggs are old and the bird's could be old too.

Is always good to use fresh eggs and is good to know the different, because sometimes the eggs whites presentation or quantity/weight  or texture is crucial during the food service or preparations.