why does we do and in 8085 microprocessor code example

Example: 8085 microprocessor code

(2501 H) = 99H 
(2502 H) = 39H 
Result (2503 H) = 99H + 39H = D2H  
Since,
   1 0 0 1 1 0 0 1 (99H) 
 + 0 1 1 1 1 0 0 1 (39H) 
   1 1 0 1 0 0 1 0 (D2H)