Mumps is caused by a virus.

Explanation:
Mumps is a viral infection that primarily affects the salivary glands, causing swelling and pain. The virus that causes mumps is called the mumps virus, which belongs to the Paramyxovirus family. It is a single-stranded RNA virus that is spread through respiratory droplets from an infected person. The virus can survive on surfaces for several hours and can be transmitted through contact with infected surfaces or objects.

Symptoms of mumps include fever, headache, muscle aches, fatigue, loss of appetite, and swollen and tender salivary glands. In rare cases, mumps can lead to serious complications such as meningitis, encephalitis, hearing loss, and infertility.

Mumps can be prevented through vaccination, which is part of the routine childhood immunization schedule. The MMR vaccine (Measles, Mumps, Rubella) is given to children at 12-15 months of age, and a second dose is given at 4-6 years of age. Vaccination not only protects individuals from mumps but also helps to prevent outbreaks and the spread of the virus in the community.