what is resistance in physics

Resistance in physics is a measure of the opposition to current flow in an electrical circuit. It is represented by the symbol R and measured in ohms, symbolized by the Greek letter omega (Ω). Resistance is the hindrance to the flow of charge, and it is caused by the collisions of electrons with fixed atoms within the conducting material. All materials resist current flow to some degree, and they fall into two broad categories: conductors, which offer very little resistance, and insulators, which present high resistance and restrict the flow of electrons. The standard unit of resistance is the ohm, and it is determined by factors such as the type and temperature of the substance, as well as its length and cross-sectional area. Resistance can be measured using a digital multimeter, which can also measure voltage, current, and other parameters