This review article discusses the molecular mechanisms that contribute to the resistance and tolerance of pathogenic bacteria in biofilm communities to antimicrobial therapy. Biofilms, which are surface-attached microbial communities encased in an extracellular matrix, are significantly less susceptible to antimicrobial agents compared to planktonic cells, making biofilm-based infections difficult to cure. The review highlights various mechanisms that enhance the resistance and tolerance of biofilm cells, including interaction with biofilm matrix components, reduced growth rates, and specific genetic determinants of antibiotic resistance and tolerance. Each mechanism alone only partially accounts for the increased antimicrobial resistance observed in biofilms, but collectively they ensure the survival of biofilm cells even under aggressive antimicrobial treatment. The review also provides historical and recent scientific data supporting these mechanisms and suggests future research directions in the field.This review article discusses the molecular mechanisms that contribute to the resistance and tolerance of pathogenic bacteria in biofilm communities to antimicrobial therapy. Biofilms, which are surface-attached microbial communities encased in an extracellular matrix, are significantly less susceptible to antimicrobial agents compared to planktonic cells, making biofilm-based infections difficult to cure. The review highlights various mechanisms that enhance the resistance and tolerance of biofilm cells, including interaction with biofilm matrix components, reduced growth rates, and specific genetic determinants of antibiotic resistance and tolerance. Each mechanism alone only partially accounts for the increased antimicrobial resistance observed in biofilms, but collectively they ensure the survival of biofilm cells even under aggressive antimicrobial treatment. The review also provides historical and recent scientific data supporting these mechanisms and suggests future research directions in the field.