TIE BEAM :-
The beam which connects two or more columns/rafters in a roof/roof truss or in any height above floor level is called tie beam. Tie beams are mainly provided in roof truss and at plinth level. These beams do not convey any floor loads and only act as length breaker for columns where the floor height is unusually high.
The main purpose of tie beam is to carry axial compression and to transfer the rafters load to the column. It also prevents column from buckling.
PLINTH BEAM :-
The beam which is provided at the plinth level is called plinth beam. In farmed structure, this beam is the first beam constructed after foundation.
The purpose of plinth beam is to distribute loads of walls over the foundation and it also connect all the columns. It also prevents cracks from the foundation to the wall. It also avoid differential settlement.