This document discusses cephalosporins, a class of antibiotics that work by interfering with bacterial cell wall synthesis. It covers four generations of cephalosporins that differ in their spectrum of antibacterial activity, with later generations having broader coverage. First-generation cephalosporins are mainly active against gram-positive bacteria. Second-generation drugs have enhanced gram-negative coverage. Third-generation cephalosporins are most potent against gram-negatives but less so against gram-positives. Fourth-generation cephalosporins have the broadest spectrum of activity. Side effects include rashes, diarrhea, and allergic reactions.