Hertz measures cycles per second - one Hertz is one cycle per second. Unlike gauss that is a measurement unit for the strenght of a specific thing (an electromagnetic field), hertz is a generic frequency measurement.
Prepend is a word that means to attach content as a prefix. It is often used in different kinds of programming and in automated processes. Some prepending is done manually as a user. For example, a prepend command could be used in a scripting language that a programmer would enter into a certain function or code module. It would add certain characters of text to the beginning of some variable or object.
Displays are made up by the manufacturer or vendor. A prepack is a number of variants of one or more generic articles that are sold as individual item. A prepack has an own article number, purchase price and purchase price conditions. Unlike displays the componenets in prepacks must belong to the same merchandise category as tthe prepack itself. Hope this helps.