A turbine was a type of energy-production technology which utilized water or other fluids to rotate a series of blades, thereby creating a usable form of power.
Constitution-class vessels utilized turbines as a supplement to the more traditional warp core. In 2258, upon using transwarp beaming to transport from the surface of Delta Vega to the USS Enterprise, Montgomery Scott was inadvertently materialized inside one of the chambers containing fluid being routed to the turbine. As Scott was pulled through the various water pipes towards the turbine, James Kirk, who had transported along with Scott, rushed to activate a release valve before Scott was killed by the turbine blades. Kirk was able to access the valve, freeing Scott from the pipe only moments before he entered the turbine. (Star Trek)