The coin in question is a 1994 Lincoln Cent - its surface has a very "rough" looking appearance. This is only the planchet background of the coin on both the obverse and reverse - the rough texture doesn't appear on the numbering or on Lincoln. Please compare pics with a "smooth" regular 2002 Lincoln Cent. Thanks in advance. - Jeff
I wouldn't exactly say it's pretty common but it's nothing special either. It adds no value to the coin but to a collector it can add interest which does make it collectible.
Actually, if you look closely, the dimpling is on the memorial and the lettering too. I'd go with either plating error, planchet defect, or a rusty die.