How does an electrically polarized object differ from an electrically charged object?

The polarized objects are charged only due to presence of an external electric field whereas an electrically charged body has a difference between the quantity of the two charges present across it bulk mass.

Explanation:

Electrically polarised body consists of both positive and negative charges of equal magnitude in the opposite directions.

The polarisation is the process of inducing a charge on an electrically neutral body (be it conductor or insulator) by bringing it into the proximity of an electric field (or charges). This attracts opposite charges on the nearest atoms of the neutral body. Also the counter charges are shifted away in those atoms developing a small dipole temporarily. The shifting of electrons (which being at the outer periphery of an atom are most susceptible to electric field) continues as a chain propagation in conductors but remains confined to the nearest atoms and fades away with distance in the insulators.

In case of an electrically charged body there is an imbalance of charges within its mass and has excess of one kind of charged particles and deficiency of the other kind of charges making it a permanently charged body.