Short answers, pulled from the story.
The Hundred Years' War took place from 1337 to 1453, a span of 116 years. It was an intermittent conflict, frequently interrupted by truces and by external factors such as the Black Death, rather than a single continuous war.
The Hundred Years' War emerged from feudal disputes over the Duchy of Aquitaine and was triggered when Edward III of England claimed the French throne. The dispute over Guyenne, where the English king held lands as a vassal of the French crown, was even more important than the dynastic question. Tensions traced back to the Norman Conquest of 1066.
France won the Hundred Years' War. French forces under the House of Valois ultimately retained control over the Kingdom of France, and England permanently lost most of its continental possessions, keeping only the Pale of Calais until 1558.
The Hundred Years' War is commonly divided into three phases separated by truces: the Edwardian War from 1337 to 1360, the Caroline War from 1369 to 1389, and the Lancastrian War from 1415 to 1453. English forces initially prevailing, but the French ultimately won.
Joan of Arc persuaded the Dauphin to send her to the siege of Orleans in April 1429, where she helped force the English to lift the siege within days. Inspired by her, the French took several English strongholds and the Dauphin was crowned Charles VII at Reims. She was captured by the Burgundians in 1430 and burned at the stake on the 30th of May 1431.
The Hundred Years' War produced the first standing armies in Western Europe since the Roman Empire and made artillery decisive, with the Battle of Castillon in 1453 the first major battle won through extensive use of field artillery. Feudal armies were replaced by professional troops, and chivalry reached its height during the conflict before declining.
Bubonic plague and warfare reduced populations across Europe, with France losing half its population during the Hundred Years' War. Normandy was reduced by three-quarters and Paris by two-thirds, while England's population fell by 20 to 33 percent.