The first thing to understand is scale. Kaş is a small harbour town, and most places to stay are small hotels and guesthouses rather than big resorts. It suits travellers who like to wander the same few streets, recognise faces by the end of the week and keep things simple.
Fethiye is a larger harbour town that acts as the hub for a whole area, including the Ölüdeniz lagoon a short drive away. That gives you more variety in where you stay and more to fill your days, with a little less of the village feel. Neither approach is better; it simply depends on whether you picture yourself in the same café each morning or setting off somewhere new after breakfast. Our guide to where to stay around Fethiye breaks the area down.