The term "-E/kT" is commonly used in statistical mechanics and thermodynamics. Here, "E" represents energy, "k" is the Boltzmann constant, and "T" is the absolute temperature measured in Kelvin. This expression is part of the Boltzmann factor, which describes the probability of a system being in a particular energy state at a given temperature. In this context, the negative sign indicates that as energy increases, the probability of finding the system in that state decreases. This relationship helps explain phenomena such as thermal equilibrium and the distribution of particles in different energy states within a system.