Bones articulate (form a joint) with others bones, (except the hyoid). Condyles are protuberences which are usually rounded, at the ends (epiphysis) of bones, especially long bones that help connective tissue (like articular cartilage, ligaments, tendons,fascia) form the articulation. In other words, the condyles are the areas that the connective tissue adheres to that help form the integrity of the joint. This is important for the strength and stability of the joints which is necessary to prevent injury and assist with everyday normal, mundane movements like walking, running, jumping, etc.
Trauma or injury to the bones in the area of any condyle is problematic because not only does the bone have to be repaired but the articular cartilage is also damaged because the underlying condyles sustained injury also.
Where bones meet, a joint is formed. According to the requirement there may be no movement allowed at the joints, a little movement possible or the ability for both the bones to move freely at the joint. Usually where the bones can move freely, an example being the knee and elbow, the two bones do not have flat ends. Instead they have protrusions with one having a hollow end and the other having a rounded end. The rounded portion is called a condyle. The condyle sits in the hollow at the end of the other bone to form a ball and socket joint. This allows for easy movement with the least damage caused and energy spent.