Historically the terms beer and ale respectively referred to drinks brewed with and without hops. It has often now come to mean a bitter-tasting barley beverage fermented at room temperature. In some British usage, however, in homage to the original distinction, it is not now used except in compounds (such as "pale ale" (see below)) or as "real ale", a term adopted in opposition to the pressurised beers developed by industrial brewers in the 1960s, and used of a warm-fermented unpasteurised beer served from the cask (though not stout or porter).
Ale typically has bittering agent(s) to balance the sweetness of the malt and to act as a preservative. Ale was originally bittered with gruit, a mixture of herbs (sometimes spices) which was boiled in the wort prior to fermentation. Later, hops replaced the gruit blend in common usage as the sole bittering agent.
Ale, along with bread, was an important source of nutrition in the medieval world, particularly small beer, also known as table beer or mild beer, which was highly nutritious, contained just enough alcohol to act as a preservative, and provided hydration without intoxicating effects. Small beer would have been consumed daily by almost everyone in the medieval world, with higher-alcohol ales served for recreational purposes. The lower cost for proprietors combined with the lower taxes levied on small beer led to the selling of beer labeled "strong beer" that had actually been diluted with small beer.
The word 'ale' is native English, in Old English alu or ealu, but aloth, ealoth in the genitive and dative. It is believed to stem from Proto-Indo-European root *alu-, through Proto-Germanic *aluth-. This is a cognate of Old Saxon alo, Danish, Norwegian, Swedish, Icelandic and Old Norse öl/øl, Finnish olut, Estonian olu, Old Bulgarian olu cider, Slovenian ol, Old Prussian alu, Lithuanian alus, Latvian alus.