ip address is a 32 bit address which contain 4 octects separated by a dots 
mac address is a 48 bit address which can be configured on a nic  card default
 in nework communication both are important with out one the other cannot be communicated if we are using ip addres to communicate means internally we use arp protocol to find out the mac address then only we can communicate

Hi Anil 
you make your best but not fully correct this is partial and you are touching only the boundary of that answers
 ip address is used for network identifictaion.where as mac address is used for the node identification.

In any network that is either it is lan or wan ip address is defined for only the network identification 

i am giving here the example i think by this i hope that you can understand

you have yours  postal address that contain
your name 
your father name 
your street name 
your district
your state
and your postal code


so in this example your name and your street is your node(mac) address where you leave and your sate and district are the  the network address that is ip

how-:
let if i am posting any thing to you by India post then what is the process

at first the people will see from which state it concern
it will send to that state now in that state people see that in which district so it will send to your district then from there it will reach to you
same concepts with the ip address and mac address.


Hope this will help you
Thank you
jitendera kumar sinha