Ringworm is a contagious fungal infection of the skin.
It can be itchy and unpleasant, but it's not painful or dangerous.
When the fungus affects the scalp, the condition is called tinea capitis, and when it affects the body it's tinea corporis.
(By the way, athlete's foot is tinea pedis, and jock itch is tinea cruris — all are caused by fungi.)
Ringworm shows up most commonly often in children over the age of 2age 2 and older , but it's possible for babies and adults to get it too.