Scoring standards are the scales against which contestants/entries are measured for a particular judging factor. You may only have ONE standard called "Execution" and you can use that standard for EVERY judging factor. For example, in a car show, let's say the judging factors are: "Interior Finish," "Exterior Finish," and "Overall Appearance." You could use the "execution" standard to grade each factor from 1-10. Simple.
In a more complex setup, like the one below, you could use multiple standards for each judging factor. An example would be a radio control helicopter flying competition in which the pilot is required to perform 3 maneuvers (takeoff, hover, land). In that case, the judges might be asked to grade "Scale Speed," "Realism," and "Precision" for each element.