The chief difference between beer and cider is that beer gets its alcohol from fermented, malted grain while cider gets its alcohol from fermented apple juice, according to Characters Pub. A number of hybrid beverages blur the line between the two, including apple beers. However, while a beer can contain fruit and other ingredients, no true cider contains malted grains.
While both beer and cider rely on fermented sugars to produce alcohol, the two beverages start from very different ingredients. Beer begins with malt, which is grain that has been germinated and then dried. This creates enzymes that break the starch inside the grain down into sugars. The brewer then adds water and yeast, and the yeast converts the sugar into alcohol. Finally, flower buds called hops are added to produce additional flavor and aroma and help preserve the beer.
Cider, on the other hand, begins with only apple juice and yeast. Since the juice already contains plenty of sugar, the yeast has more than enough available to produce its alcohol. Ciders and beers tend to have similar alcohol content, but since the cider begins with a sweet beverage instead of converted starches, cider often has a higher carbohydrate content than beer.