One of the ways a knight could practice and improve his skills without actually going into battle was to enter a tournament. In addition to practice, a knight could win public acclaim as well as money by winning a tournament.
The tournament area would be either walled off with a temporary fence or maybe just roped off. The nobles sat in wooden stands while the commoners would sit in the fields nearby to watch. A tournament was a big event and people came from far away to watch.
A tournament's activities included all the skills a knight was supposed to have. There would be fighting of all types as well as contests of poetry and song. The two favorite events were the joust and melee.
Jousting was combat between two knights. The two started from opposite sides of a field and charged their horses towards each other. The goal was to knock the other knight off his horse. They started with lances then when the lances broke they used swords or axes. Broken bones and even death were normal to the joust.
Melee was combat between two teams of knights and squires. The goal was to capture the flag each knight and squire had on their back. They wore armor and used swords, axes and clubs to do this. Again broken bones and deaths were common.
Jousting is still practiced today (with a lot more safeguards in place to limit injury) at many Renaissance fairs and tournaments and is practiced by the Society for Creative Anachronism.