In this work, we review the basics of both ideal and non ideal rnuid dynamics. Funda-rnmental principles of rnuid dynamics,solution of nonlinear Boltzmann equation, transportrncoe cients, and moment transfer, are discussed. To solve the collision integral we havernused the concept of time reversal symmetry. The basic equations governing rnuid motionrn, energy and momentum are discussed. The inrnuence of viscosity and its time and tem-rnperature dependency in rnuid motion is also discussed. These concepts are then appliedrnsystematically in Neutron star matter to obtain the general balance equation and to in-rnvestigate the motion of rnuid particles between two parallel planes moving with a constantrnrelative velocity . Di erence between ideal and non ideal rnuids are discussed