Roseola is a common viral infection that primarily affects young children, typically between the ages of 6 months and 2 years. It is caused by the human herpesvirus 6 (HHV-6) and is characterized by a sudden high fever that lasts for a few days, often followed by a distinctive pinkish-red rash that appears as the fever subsides. The rash usually starts on the trunk and then spreads to the face and limbs. While roseola is generally mild and resolves on its own, it can sometimes lead to complications like febrile seizures due to the high fever. Most children recover fully without any long-term effects.