A public house, usually known as a pub, is an establishment which serves alcoholic drinks for consumption on the premises, usually in a homely setting. Pubs are commonly found in English-speaking countries, particularly in the United Kingdom, Ireland, Canada, Australia and New Zealand.

In North America, drinking establishments with a British or Irish name or theme are called pubs as well; the appellation "pub" itself it often a component of this theme. Although the terms may have different connotations, there is no definitive difference between pubs, bars, taverns and lounges where alcohol is served commercially.

Traditionally, a pub which offers lodging may be called an inn or (more recently) hotel in the UK, although today many pubs with the word "inn" in their name no longer do, or in some cases have never done so. Similarly, in Australia, pubs often bear the name of "hotel", because historically only hostelries were allowed to serve alcohol, even though many no longer offer lodging (hotels which offer only lodging, without a bar, are generally called "private hotels").

source: http://en.wikipedia.org