Amoxicillin 500mg is a penicillin-class antibiotic used to treat bacterial infections of the ear, nose, throat, lower respiratory tract (such as bronchitis and pneumonia), urinary tract, and skin, and it is part of combination therapy to eradicate Helicobacter pylori in peptic ulcer disease. It works by inhibiting bacterial cell wall synthesis, leading to bacterial death. Amoxicillin does not treat viral illnesses, and inappropriate use can promote resistance; therapy should follow a clinician’s prescription and local guidelines.