From a Korean-America standpoint, the best way I explain the difference to a Westerner from America is: Seoul dialect = your “normal” American pronunciation spoken in most states (ex: Washington D.C./Northern Virginia area), while Busan dialect = Southern accent in regards to America (ex: Alabama, Texas, etc). This analogy is used to show that the way they pronounce certain words are different and even have different ways to say things. I personally like the Busan dialect better and really wish I can speak like them. The Busan dialect has a bit more swag~~ :)