What category of resources are diary entries and letters?

Diary entries and letters fall into the category of primary sources.

Here's why:

* Primary sources are original materials created during the time period being studied. They offer firsthand accounts and perspectives.

* Diary entries and letters are written by individuals directly involved in the events they describe. They provide insights into personal experiences, opinions, and daily life.

In contrast, secondary sources are materials that interpret, analyze, or discuss primary sources. Examples include textbooks, biographies, and articles.