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.
The append command can be used by programs to open files in another directory as if they were located in the current directory. The append command is not available in 64-bit versions of Windows 7. Arp. The arp command is used to display or change entries in the ARP cache.