Change of plan from home combo 500 to 625-Difference ?

Can any one explain difference of broadband usage in new plan opted combo 625?

Hi..

The BSNL Broadband plan 500 was I suppose with 1.5 GB included data transfer and some 100+ monthly calls free and yes with 2mbps download speed. Now in plan 625 you get Unlimited download at 256kbps with 100 free calls every month.