Pansy or viola?

 I am still yet to fully understand the difference between a pansy or viola! Anyhow, despite the fact that they are extremely common place I still think they are quite beautiful! Whilst dead-heading some pots of them earlier I accidently wounded this poor one... & decided to make him into a button hole. - I think it has a lovely gypsy look to it! 

There were so many stunning shades of pansies at Chelsea...