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.
PrEP, an acronym from Pre-Exposure Prophylaxis, is the use of prescription drugs by people who do not have HIV/AIDS as a strategy for the prevention of HIV/AIDS.he terms pre-exposure prophylaxis and PrEP most commonly refer to an HIV-prevention strategy where antiretrovirals are used to protect HIV-negative people from HIV infection.