Caterpillar is a company that manufactures construction and mining equipment, diesel and natural gas engines, industrial gas turbines, and diesel-electric locomotives. It operates through four segments: Construction Industries, Resource Industries, Energy & Transportation, and Financial Products. The Construction Industries segment is primarily responsible for supporting customers using machinery in infrastructure, forestry, and building construction. The Resource Industries segment supports customers using machinery in mining, heavy construction, quarry and aggregates, waste, and material handling applications. The Energy & Transportation segment offers reciprocating engines, generator sets, marine propulsion systems, gas turbines and turbine-related services, etc. The Financial Products segment provides retail and wholesale financing alternatives to customers and dealers.