What are the different duties and areas of design between an architect, urban planner/designer and landscape architect?

I am looking into these fields. I imagine each profession designs different parts of a city. I know architects focus on buildings, and urban planners focus on the continuation and changing and upkeep of cities, and i think landscape architects focus on outside areas, pavilions, public spaces and the sort. I am looking to find out which designs which parts of a city, or if one profession can encompass all parts of a city. I am also looking to find out which is the most broad role and can do the roles of the others. I imagine that architecture can encompass both urban design and landscape architecture. I also know that architects do master planning. If anyone in the field knows, Id appreciate your feedback. Thanks