In a general sense, dose is a measure of the amount of energy from an ionizing radiation deposited in a mass of some material. Dose is affected by the TYPE of radiation, the amount of radiation and the physical properties of the material itself. Specifically, we can talk about absorbed dose in tissue, or a material like silicon. Other common doses are the effective and equivalent doses, which are adjusted to allow the comparison of different tissues or types of radiation. Absorbed doses are normally measured in units of Gray (RAD), and effective and equivalent doses in Sievert (Rem).