AND is an instruction that takes an 8-bit input an compares it with the accumulator. It checks to see if both are set. If either one is reset, the resulting bit in the accumulator is zero.
0 and 0 result: 0
0 and 1 result: 0
1 and 0 result: 0
1 and 1 result: 1
and a and b and c and d and e and h and l and ixh and ixl and iyh and iyl and (hl) and (ix+n) and (iy+n) and n ;8 bit constant
C and N flags cleared, P/V is parity, rest are altered by definition.
The most important use of AND is in bit-masking. For more information on bit-masking, see here.
r denotes 8-bit register.