Transporters, also known as carriers or permeases, are a type of membrane transport protein that traverse the membrane of cells and cellular organelles. These facilitate a controlled exchange of essential solutes across the cell membrane. Transporters can be of three types: uniporters, symporters, and antiporters based on their transport mechanism. Uniporters allow diffusion or passive transport of a single type of solute from its higher to its lower concentration to attain equilibrium. Whereas, symporters or cotransporters allow the simultaneous transport of two different solutes in the same direction. In contrast, antiporters allow net transport of two different solutes simultaneously in the opposite direction. The solutes' movement across the membrane can either be passive as seen for uniporters or active as in symporters or antiporters. The active transport could gain energy from direct ATP hydrolysis. In contrast, some active transport can also power one solute's movement by coupling its transport with another solute. This transport mechanism is known as secondary active transport.