One hundred is the smallest three digit number in the decimal system and the smallest square of a two-digit number (10). A hundred today means 100 but, over the years and in different places, it has stood for different values including 112, 120, 124, and 132. The remnants of these old measures still persist in the hundredweight of some countries representing 112 or 120 lb. A hundred is also a measure of land area, frequently used in colonial America and in England to signify a division of a county or a shire having its own court. A strange custom is invoked if a member of the English Parliament's lower house, the House of Commons, wishes to resign his seat (something that is technically illegal). An MP accepts stewardship of the "Chiltern Hundreds," an area of chalk hills near Oxford and Buckingham, which effects his release from Parliament. The so-called "Hundred Years War" between the English and the French actually lasted 116 years.
A century is a period of 100 years. The original Latin centuria means simply 'one hundred' and was used to describe any collection of 100 items. In the Roman army, a century was a group of 100 men, each known as a centurion. One of the few modern examples of "century" being used other than to denote a period of time is in the game of cricket where a batsman who scores 100 runs in an innings is said to have 'made a century'.