Compressors are machines that increase the pressure of natural gas in order to move it from point A to point B. Pumps serve the same purpose for oil pipelines. Compressors and pumps can either be used at the wellhead or at a central location along a pipeline, where several compressors or pumps are usually grouped together at a facility called a compressor or pump station. The number of compressors or pumps at a station or stations will vary based on the amount of production from nearby wells, the size of the pipeline and the distance the product has to travel to the next station or pipeline market. Other treating equipment, such as separators and dehydrators, may also be located at these stations to remove impurities and entrained water vapors from the oil or gas.