First of all, the configurations of an optical disc, which is used as an information recording medium, and {HEAD ~ an optical disc drive}, which is used as {TAIL ~ an information} read/write apparatus, will be described 
is used as
First of all , the configurations of an optical disc , which is used as an information recording medium , and { HEAD ~ an optical disc drive } , which is used as { TAIL ~ an information } read / write apparatus , will be described
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH