Does not and doesn't difference?

I'm curious about the difference between "does not" and "doesn't." Are they interchangeable in all contexts, or are there specific situations where one should be used over the other? As a language enthusiast, I want to ensure that I'm using the correct form to convey my meaning accurately. Additionally, I'm interested in knowing if there are any stylistic or regional preferences when it comes to choosing between these two phrases. Could you elaborate on the differences and provide some examples to illustrate when each should be used?