Hostels offer a very social atmosphere and the chance to meet new people from all over. I flew from Madrid to Zurich, Switzerland and I was traveling alone for the first time. Although no specific type of building defines hostels, they can be old apartment-complex buildings, old school buildings or old rooming houses. The type of room ranges from large rooms with a lot of bunk beds to private rooms. Summer is the peak season, so it is a good idea to call ahead or arrive in the afternoon to look for somewhere to stay.
Some hostels also provide excursion possibilities, laundry facilities and kitchen access.
Although hostels are a great place to meet people, their raucous atmosphere can be a deterrent for some. The lack of privacy may also be an issue. Another option that is more expensive is the pensions. These are generally small, family-run hotels that can also be found in guidebooks. It is important to look at rooms before you commit to staying there.