If DNA is genetic material of life then if we got DNA from parents and then also our DNA is different why? When DBA is genetic material of life then why genes are not explain?

DNA, we are getting DNA from our parents not from our parent so DNA of our both parents is our DNA

It is rather the law of variance

see, DNA that we have inherited from our parents is 99% same  except that 1% dna sequence which make every one different from their respective parents. It can be physical apperance like your eye, face structure,height,colour,hair etc etc...

see the nature that 1% dna sequence make every one unique.... 

 

50% of our genetic material is from mother and 50% is from father still we have dissimilar dna..99.9% of base sequence among humans is same. Dna fingerprinting involves identifying these differences in some specific regions of DNA Sequence called as repetitive dna. These are separated from bulk dna as different peaks during density centrifugation. Hope it helps.