Travellers hostels

The traditional hostel format involved dormitory style accommodation. Some newer hostels include en-suite accommodation with single, double or quad occupancy rooms, though to be considered a hostel they must also provide dormitory accommodation[1][2]. In recent years the numbers of independent and backpackers' hostels has increased greatly to cater for the greater numbers of overland, multi-destination travellers (such as gap-year travellers, railtrippers, those on sabbaticals etc.)
The quality of such places has also improved dramatically. Whilst some hostels do still insist on a curfew, daytime lockouts, and/or require occupants to do chores, this is becoming the exception rather than the rule, as hostels adapt to meet the changing expectations of guests[3].

[edit] 'Youth Hostel' - beginnings

Aichi Ken Seinen Youth Hostel in Nagoya, with wa-fu (Japanese-style) rooms.
In 1912 in Altena Castle in Germany, Richard Schirrmann created the first permanent Jugendherberge or 'Youth Hostel' (now a trademark of the former International Youth Hostel Federation or IYHF). These first Youth Hostels were an exponent of the ideology of the German Youth Movement to let poor, city youngsters breathe fresh air outdoors. The youths were supposed to manage the hostel themselves as much as possible and do chores to keep the costs down and build character as well as being physically active outdoors. Because of this, many Youth Hostels closed (and still close) during the middle part of the day.
The idea rapidly spread overseas and eventually resulted in Hostelling International (HI), a non-profit organization composed of more than 90 different Youth Hostel associations representing over 4500 Youth Hostels in over 80 countries.
Some HI Youth Hostels cater more to school-aged children (sometimes through school trips) and parents with their children, whereas others are more for travellers intent on learning new cultures. However, while the exploration of different cultures and places is emphasized in many hostels, particularly in cities or popular tourist destinations, there are still many hostels providing accommodation for outdoor pursuits such as hillwalking, climbing and bicycle touring and these are often small friendly hostels that retain much of the original vision and often provide valuable access to more remote regions.
Despite their name, in most countries membership is not limited to youth.

[edit] Independent travellers' or Backpackers' hostels
Independent hostels are not necessarily affiliated with one of the national bodies of Hostelling International, Youth Hostel Association or any other licensing body.
The term "youth" is less often used with these properties. These unaffiliated hostels are often called "backpackers' hostels" and can be more or less expensive. Unlike a fast food restaurant where everything is standardized, these hostels can be very diverse. They usually do not require a membership card. Being privately-owned, these hostels can offer the latest technology and services for guests. One of the first US hostel chains to promote this new "socialized hotel" was Banana Bungalow in the early 1990s. Youth Hostels have since become places to meet people rather than just accommodation.