which is more better distance learning or traditional learning?:)

Neither is *more* better. Each individual will need to decide for themselves what works best for them.

Having acquired my degree via a distant education course I could give you below my own "pros" and "cons":

Distant education:

Positives: can study and work, which means you will gain experience as well as a qualification / don't need to move from the place where you live / good for mature learners with a family and kids / is often cheaper in terms of tuition fees / teaches self discipline

Negatives: need great self discipline / have to be able to study from books mainly (i.e. most of the time you won't have a tutor to explain to you) / you won't get the "student life" - meet new people, partying, etc

Of course there is lots more to add, but I hope that the above is helpful.

I want to know if Washington university is an accredited on line university or no

Thank you. It really helps me a lot:)