what is Seebeck effect

In 1821, German Physicist Thomas Johann Seebeck discovered that in a circuit consisting of two dissimilar metals like iron and copper, an emf is developed when the junctions are maintained at different temperatures. Two dissimilar metals connected to form two junctions is called thermocouple. The emf developed in the circuit is thermo electric emf. The current through the circuit is called thermoelectric current. This effect is called thermoelectric effect or Seebeck effect. 

when two dissimilar metals are joined in series to form a cl0sed circuit ad their junctios are mantained at different temp an emf is developed this phenomenon is called seebeck or thermo electric effect