Symporter
A type of coupled transporter that simultaneously transfer a second solute in the same direction as the first. The tight coupling transfer of the two solutes allows the coupled transporters to obtain energy stored in the electrochemical gradient of the first solute to transfer the second one [1]. The free energy released during the 'downhill' movement of one solute is used to power the 'uphill' movement of the other solute in the same direction. These transporters will only transport both solutes at the same time, no one solute can be transported independantly[2] .
Sodium is usually the co-transported ion that provides the driving force for transporting the second molecule.