Old horses are a common sight in many parts of the world. The term 'old horses' can refer to three different types of horses: nags, JADES, and plugs. Nags are old, worn-out horses that are no longer useful for riding or work. JADES are horses that have been used for a long time and are now considered too old for riding or work. Plugs are horses that are past their prime and are used mainly for light work or transportation. All three types of old horses are often retired from active service and kept as pets or companions.