The study investigates the structural correlates of neutralizing antibodies against SARS-CoV-2, which are crucial for therapeutic strategies. Eight new structures of human neutralizing antibodies in complex with the SARS-CoV-2 spike trimer or receptor-binding domain (RBD) were solved to understand their mechanisms of action. The antibodies were classified into four categories based on their binding characteristics: (1) VH3-53-encoded antibodies with short CDRH3 loops that block ACE2 and bind only to 'up' RBDs; (2) ACE2-blocking antibodies that bind to both 'up' and 'down' RBDs; (3) antibodies that bind outside the ACE2 site and recognize both 'up' and 'down' RBDs; and (4) previously described antibodies that do not block ACE2 and bind only to 'up' RBDs. Class 2 antibodies, including a VH3-53 antibody, use a long CDRH3 loop to bridge adjacent RBDs, locking the spike into a closed conformation. Epitope and paratope mapping revealed minimal interactions with host-derived N-glycans and minor contributions from somatic hypermutations. Affinity measurements and mapping of spike mutants provided insights into potential viral escape mechanisms. These findings provide rules for classifying and evaluating human RBD-targeting antibodies, suggesting combinations for clinical use and offering insights into immune responses against SARS-CoV-2.The study investigates the structural correlates of neutralizing antibodies against SARS-CoV-2, which are crucial for therapeutic strategies. Eight new structures of human neutralizing antibodies in complex with the SARS-CoV-2 spike trimer or receptor-binding domain (RBD) were solved to understand their mechanisms of action. The antibodies were classified into four categories based on their binding characteristics: (1) VH3-53-encoded antibodies with short CDRH3 loops that block ACE2 and bind only to 'up' RBDs; (2) ACE2-blocking antibodies that bind to both 'up' and 'down' RBDs; (3) antibodies that bind outside the ACE2 site and recognize both 'up' and 'down' RBDs; and (4) previously described antibodies that do not block ACE2 and bind only to 'up' RBDs. Class 2 antibodies, including a VH3-53 antibody, use a long CDRH3 loop to bridge adjacent RBDs, locking the spike into a closed conformation. Epitope and paratope mapping revealed minimal interactions with host-derived N-glycans and minor contributions from somatic hypermutations. Affinity measurements and mapping of spike mutants provided insights into potential viral escape mechanisms. These findings provide rules for classifying and evaluating human RBD-targeting antibodies, suggesting combinations for clinical use and offering insights into immune responses against SARS-CoV-2.