Accent refers to pronunciation. Dialect refers to a whole group of language features, including pronunciation, but also differences in vocabulary, grammar, and how the language gets used. You can change your accent by changing your pronunciation of words. However, the words you choose to use and how you use them determines your dialect. Dialect is a sort of "frame of reference." Accents and dialects can come from your geographical location. For example, USA and England share a language, but both have different dialects. British people can talk with an American accent and Americans can talk with a British accent, but what we call things are different - for example, "elevator" vs "lift." Accent is like the color paint you choose for your house, whereas, dialect is the shape of the house. Accent is like the dressing on the cake, but the dialect is like the ingredients.