What are the objectives of annealing?

Slow cooling rate from the eutectoid temperature yields course pearlite - a mixture of relatively coarse crystals of ferrite and cementite. Such a slow cooling is known as annealing. Here, sufficient time is available for the carbon in the austenite to disperse and redistribute itself to 0.02% in ferrite and 6.67% in cementite. During annealing, effective transformation temperature is decrease, where the rate of growth is rapid compared to the rate of nucleation. Therefore, spheroidising is obviously different from annealing.