Simplify the following text for a Grade 4 native English-speaking person.
Original: Public bus service is provided by the Greater Peoria Mass Transit District , which operates 20 bus routes under the name CityLink , that serve the city , Illinois Central College and much of East Peoria , Illinois , Peoria Heights , West Peoria , and points between Peoria and Pekin , Illinois .
Simplified: Peoria is a city on the Illinois River in the U.S. state of Illinois . In the 2000 census , Peoria had more than 110,000 people living in it .