Electrical resistance refers to the property of a material or component that opposes the flow of electric current. It is a fundamental concept in electrical engineering and physics, where materials with higher resistance impede the flow of electrons more effectively than those with lower resistance. Resistance is measured in ohms (Ω) and is denoted by the symbol R in electrical equations.

In simple terms, electrical resistance can be understood as the friction that electrons encounter as they move through a conductor. When an electric potential (voltage) is applied across a conductor, such as a wire or a resistor, electrons flow from the higher potential to the lower potential. Resistance limits this flow, causing some of the electrical energy to be converted into heat as the electrons collide with atoms in the material.

Electric resistance is often simply referred to as resistance in common usage. It is an inherent property of materials and is influenced by factors such as the type of material, its dimensions, and temperature. The resistance of a material is typically characterized by its resistivity (ρ), a material-specific property, and its physical dimensions. The formula relating resistance, voltage (V), and current (I) is Ohm’s law: R = V / I, where R is resistance, V is voltage, and I is current.

In essence, resistance in electrical terms describes how effectively a material resists the flow of electrical current and converts electrical energy into other forms such as heat. It is a fundamental parameter used in designing circuits, calculating power dissipation, and ensuring the proper operation of electrical and electronic devices.