Letters refer to written messages that are sent from one person to another, often sharing information or experiences. In this context, letters specifically refer to Christopher Columbus's written accounts about his voyages.
Communication: Communication is the exchange of information between individuals using various methods such as speaking, writing, or signaling. The letters allowed for communication between Columbus and those interested in his voyages.
Documentation: Documentation refers to recording or preserving information through written evidence. In this case, Columbus's letters served as important documentation for future generations about his expeditions.
Historical Sources: Historical sources are materials that provide information about events or people from a particular period in history. The letters written by Columbus are considered valuable historical sources for studying European exploration.