title: Computer networks-Subnet mask
body: <p>Is <strong>255.0.255.0</strong> a subnet mask? 
  If yes, then why?
  The reason I thought is its a subnet mask of either class A(N.H.H.H) or class B (N.N.H.H). If there are 255 Network thrn there should be 255 hosts. Please correct me of I am wrong. I am learning the basics of computer networks</p>