Scotch is the name for the whisky made in Scotland (so-spelled there, rather than "whiskey"). Whisky has been produced in Scotland for a long time, sometimes illegally. The name is a transformation of the word usquebaugh, itself a transformation of the Scots Gaelic uisge beatha and Irish Gaelic uisce beatha, literally meaning the "water of life".
Scotland is divided into a number of regions that produce whiskies with different regional characteristics: /Highland, /Lowland, /Speyside, /Islay, and /Campbeltown. These characteristics are described by words like smoky, peaty, seaweedy, etc.
There are two different distilling methods used to create Scotch whisky: grain distilling and malt distilling. These two processes are essentially similar, with malted barley used in malt distilling. Typically, the grain whisky is considered to be coarser than a fine malt whisky and therefore is used as part of blended whiskies.
Once distilled, the product must be left to mature in old Sherry casks for at least 3 years to be called Scotch whisky, although most single (unblended) malts are offered at a minimum of 8 years of age. The older the whisky, the better the flavour although they tend to level off after 25 years or so.