c# (excel file & datagridview comparison)

Question

 hi..

excel file contains:

name   password

abc      123

xyz      321

asas     856

jklo      854

 datagridview contains:

 name   password

abc       123

xyz       321

so question is how to compare excel file & datagridview. & show thier difference in

another datagridview... please help.. new to this...