Pharmacovigilance involves monitoring the safety of drugs on the market. It is important for improving patient care and safety, as shown by the thalidomide tragedy. Key aspects of pharmacovigilance include timely reporting and assessment of adverse drug reactions and signals to identify relationships between drugs and side effects. Causality assessment tools are used to evaluate reported adverse events and determine if the drug likely caused the reaction. Pharmacovigilance systems help manage this process from case intake to reporting.