Erbium-Doped Fiber Amplifiers (EDFAs) are devices used in optical communication systems to boost the strength of light signals. They work by using a special type of glass fiber that is infused with erbium, a rare earth element. When a weak light signal passes through this fiber, it stimulates the erbium ions, which then emit additional light at the same wavelength, amplifying the signal. EDFAs are particularly valuable in long-distance fiber optic networks, as they can amplify signals without converting them to electrical signals first. This allows for faster and more efficient data transmission over vast distances, making them essential for modern telecommunications infrastructure.