The unit of measurement for electric resistance is the ohm, symbolized by the Greek letter omega (Ω). It quantifies how much a material opposes the flow of electric current, influencing how well electrical circuits function. The concept of resistance arises from the material properties and dimensions of a conductor; for example, thicker and shorter conductors usually have lower resistance compared to thinner and longer ones. Ohm's Law, which states that Voltage = Current x Resistance, forms the foundation of electrical engineering and physics, allowing for the calculation and understanding of electrical circuits and components.