The article discusses the updated functional classification of β-lactamases, which are enzymes that hydrolyze β-lactam antibiotics, leading to bacterial resistance. The classification is based on the 1995 proposal by Bush et al., incorporating substrate and inhibitor profiles to group enzymes by their clinical roles. The updated system includes three main groups: Group 1 (class C) cephalosporinases, Group 2 (classes A and D) broad-spectrum, inhibitor-resistant, and extended-spectrum β-lactamases and serine carbapenemases, and Group 3 metallo-β-lactamases. Each group has subgroups based on specific enzyme characteristics. The classification aims to correlate enzyme properties with clinical resistance profiles, aiding in the selection of appropriate therapies. The article also highlights the increasing diversity and prevalence of β-lactamases, particularly extended-spectrum β-lactamases (ESBLs) and carbapenemases, which pose significant challenges in treating infections. The classification system is essential for tracking and understanding the evolution of these enzymes, which are often spread through horizontal gene transfer. The authors emphasize the importance of a systematic approach to classify these enzymes, considering both structural and functional characteristics. The updated classification reflects the growing complexity of β-lactamase diversity and the need for accurate identification and characterization to combat antibiotic resistance.The article discusses the updated functional classification of β-lactamases, which are enzymes that hydrolyze β-lactam antibiotics, leading to bacterial resistance. The classification is based on the 1995 proposal by Bush et al., incorporating substrate and inhibitor profiles to group enzymes by their clinical roles. The updated system includes three main groups: Group 1 (class C) cephalosporinases, Group 2 (classes A and D) broad-spectrum, inhibitor-resistant, and extended-spectrum β-lactamases and serine carbapenemases, and Group 3 metallo-β-lactamases. Each group has subgroups based on specific enzyme characteristics. The classification aims to correlate enzyme properties with clinical resistance profiles, aiding in the selection of appropriate therapies. The article also highlights the increasing diversity and prevalence of β-lactamases, particularly extended-spectrum β-lactamases (ESBLs) and carbapenemases, which pose significant challenges in treating infections. The classification system is essential for tracking and understanding the evolution of these enzymes, which are often spread through horizontal gene transfer. The authors emphasize the importance of a systematic approach to classify these enzymes, considering both structural and functional characteristics. The updated classification reflects the growing complexity of β-lactamase diversity and the need for accurate identification and characterization to combat antibiotic resistance.