What is the part of a system that defines the extent of the design pursuant to the operational requirements?

In which part of a professional email should you try to be brief, but highly descriptive?

When early motion pictures played in movie theaters, they were often accompanied by live organ or piano music. which of the following are the most likely reasons that this happened? (select all that apply). the music was provided to distract audience members from the loud sounds made when filmstrips were changed. the music accompanied the movies because the movies were silent and audiences were used to hearing music during plays in theaters. the music usually was played before, and sometimes after the movie, as an alternative form of entertainment. the music viewers to interpret the dramatic action in the films.

The more powerful, 60 volt cables and the main power shut off on an hev are both colored orange