A capstone project is a culminating education project meant to display a student's abilities to use the knowledge he or she has gained during her education in a given program. Depending on the discipline a student has chosen, a capstone can take many forms.
The term capstone comes from the final piece in the construction of an arch. This is also known as the keystone. After all pieces except for the top, center piece are in place, the final piece is placed. The pressure and friction of the final piece holds all of the others in place. A capstone project serves a similar function. After students have completed the majority of their coursework in a given field, they create a project that ties that coursework together. For instance, a capstone project for an art student might be a senior art show exhibiting the artists work throughout the student's academic career. A student focusing on conservation might do field research and create a comprehensive study of the changing populations of a given animal in a park. No matter the final form of a capstone project, the purpose is always to encourage students to engage with the knowledge the student has gained through the academic studies.