The interaction of charged and polarizable particles with static electric fields is a fundamental problem in classical electrostatics and has direct relevance to electrostatic precipitation, particle separation, colloidal processing, microfluidics, aerosol control, and biomedical manipulation. This paper examines the polarisation behaviour of charged particles in uniform and non-uniform static electric fields by distinguishing the force associated with net electrical charge from the force created by field-induced polarisation. A particle carrying net charge q in an electric field E⃗ experiences the Coulomb force qE⃗. At the same time, the field may redistribute bound or mobile charges within the particle and its interface, creating an induced dipole moment. In an ideal uniform field, the forces acting on the two poles of an induced dipole balance, so the dipole alone produces no net translational force, although torque, orientation, interfacial charge redistribution, and deformation may occur. In a non-uniform field, the two poles experience different field strengths, generating a net gradient-dependent polarisation force. This effect is the basis of dielectrophoresis. The paper develops the classical equations governing these processes, compares particle response in the two field configurations, and discusses the effects of particle size, charge, permittivity, conductivity, shape, medium viscosity, and electric-field gradient. The analysis shows that practical particle motion frequently results from the combined action of Coulombic, polarisation, hydrodynamic, and thermal forces. Understanding these mechanisms is essential for predicting and controlling particle transport, trapping, separation, and assembly in electrostatic systems.