CHP provides both electric power and thermal energy (heat) from a single fuel source, typically gas.
CHP works by supplying high temperature heat from a large boiler. This heat drives a gas or steam turbine-powered generator, to produce electricity. The remaining heat is then used to heat water. The water is transported through super insulated pipes to be used locally to heat homes and businesses. The electricity can either be used locally, or can be exported to the grid.
Your car engine in winter works a bit like CHP.
The engine powers the car, and the waste heat produced is used to warm the
interior.