Parties are Island-wide events that happen every month or so on Club Penguin, planned by the Party Commitee, usually in celebration of something. Parties notably change the appearance of Club Penguin, such as a buildings exterior and interior being changed with decorations and different Music. If you visit all of the decorated party room you would get the Explorer Stamp
The Winter Ball 2011 was going to be a party where penguins had to choose someone to go to the Winter Ball with them, similar to Proms. However, this was cancelled because it was a bit too grown-up. This was the only cancelled party that was planned and was designed.