A donor portrait or votive portrait is a portrait in a larger painting or other work showing the person who commissioned and paid for the image, or a member of his, or her, family. Donor portrait usually refers to the portrait or portraits of donors alone, as a section of a larger work, whereas votive portrait may often refer to a whole work of art intended as an ex-voto, including for example a Madonna, especially if the donor is very prominent. The terms are not used very consistently by art historians, as Angela Marisol Roberts points out, and may also be used for smaller religious subjects that were probably made to be retained by the commissioner rather than donated to a church.

An altarpiece is an work of art in painting, sculpture or relief representing a religious subject made for placing at the back of or behind the altar of a Christian church. Though most commonly used for a single work of art such as a painting or sculpture, or a set of them, the word can also be used of the whole ensemble behind an altar, otherwise known as a reredos, including what is often an elaborate frame for the central image or images. Altarpieces were one of the most important products of Christian art especially from the late Middle Ages to the era of Baroque painting.