Cider is an alcoholic beverage made from the fermented juice of apples.The juice of any variety of apple can be used to make cider, but cider apples are best. The addition of sugar or extra fruit before a second fermentation increases the alcoholic content of the resulting beverage. Cider is popular in the United Kingdom, especially in the West Country, and widely available. The UK has the world's highest per capita consumption, as well as its largest cider-producing companies.Cider is also popular in other European countries including Ireland, Portugal (mainly in Minho and Madeira), France (in particular Brittany and Normandy), northern Italy (Piedmont and Friuli), and Spain (especially Asturias and the Basque Country). Central Europe also has its own types of cider with Rhineland-Palatinate and Hesse producing a particularly tart version known as Apfelwein.

Cider alcohol content varies from 1.2% ABV to 8.5% or more in traditional English ciders, and 3.5% to 12% in continental ciders. Under UK law, it must contain at least 35% apple juice (fresh or from concentrate), although CAMRA says that "real cider" must be at least 90% fresh apple juice. In the US, there is a 50% minimum. In France, cider must be made solely from apples.

The flavour of cider varies. Ciders can be classified from dry to sweet. Their appearance ranges from cloudy with sediment to completely clear, and their colour ranges from almost clear to amber to brown. The variations in clarity and colour are mostly due to filtering between pressing and fermentation. Some apple varieties will produce a clear cider without any need for filtration. Both sparkling and still ciders are made; the sparkling variety is the more common.

Modern, mass-produced ciders closely resemble sparkling wine in appearance. More traditional brands tend to be darker and cloudier. They are often stronger than the mass-produced varieties and taste more strongly of apples. Almost colourless, white cider has the same apple juice content as conventional cider but is harder to create because the cider maker has to blend various apples to create a clearer liquid. White ciders tend to be sweeter and more refreshing. They are typically 7-8 % ABV in strength. Black cider, by contrast, is dry amber premium cider which has an alcohol content of 7-8 % ABV. The descriptor black usually comes after the brand name such as Union Black and Barnstormer Black.

Although Cider makes the perfect aperitif, the range of styles available means it can equally be at home with a versatile range of foods. The fresher Cider styles are ideal with light foods such as seafood, while the more complex Ciders are a better match with red and white meats.