What is a music parameter? Name and describe the three categories of parameters.

If you could at least explain what a parameter is that would be great. I looked it up but I don't understand the definition.

Parameters in music are elements of music which can be composed independently of the other elements, common parameters are tone, color, timbre, rhythm, melody, dynamics, texture, harmony, form, text. In a musical score, these elements are combined to create an overall unique piece of music.