In the case of the motor it is the rotor and the stator and for the pump it is the impeller and the volute (or diffuser). Of course the friction produced by bearings and other mechanical components (seals, stuffing box, etc) also affect pump efficiency, but the impeller and volute have the greatest influence. Lets start our investigation of centrifugal pump efficiency with the impeller.
The differences are minor: 1  A blazer refers to a sportcoat that is made of navy wool, with brass buttons. 2  A suit jacket is the jacket part of a suit. 3  A sport coat is a jacket, cut like a suit jacket or blazer, that doesn't have an accompanying pair of pants - it's a standalone jacket.
And then there are suit jackets. Likewise, the difference between a sport coat and a suit jacket is also subtle but worth noting. The main difference: A suit jacket has a matching pair of pants and a sport coat does not. After that, the sport coat is often made of more casual fabrics than a suit jacket, and sometimes a sport coat has a looser, more casual fit.