A hostel is budget-oriented lodging that typically rents individual beds in shared, dormitory-style rooms and offers limited services (often a common kitchen and social spaces). A hotel generally provides private guest rooms—usually with private bathrooms—and fuller front-desk and room amenities.
Washington State lodging rules define a hostel as a transient accommodation offering lodging and limited services to guests for a rental fee (or fee plus labor). Travelers often pick hostels for lower cost and a more social stay, and hotels when they want privacy and more services.
Source: Washington Administrative Code 246-360-010 (definitions, including hostel)