power facter - it is the sine angle between voltage vecter
and current vecter. 

suppose you have 1.5 kw watt motor running on 230 volts and
power facter of your motor is .65 than your current requirement 

i =p/volts*power facter
i =1500/230*0.8
i =8.15 amp.

and if you will improve power facter of your motor up to
0.85 than current requirement is 

i=p/volts*power facter
i=1500/230*0.85
i=7.67 amp.

as you can see current taken by your motor is less if you
will improve your power facter.

advantages in big inductive machine & load.
1) current is less so losses should be less.
2) less current decrease your cable size & cost
3) voltage regulation should be good.
4) rating of switch gear will less.
and finally you will get some advantages from government if
you have big factory.

hai mehul how  we can improve power factor from 0.8 to 0.85
or 0.9 & its either lag or lead ?please clear me thank you

hai ramya.

there is a lot of way to increase power facter of your
machine or factory. 

just read the book of b. l. thareja.