The article discusses the phenomenon of bacterial adhesion and biofilm formation, highlighting its ecological and evolutionary advantages. Bacteria tend to colonize surfaces rather than remain nomadic, and this behavior is advantageous for ecological interactions and survival. The article emphasizes that bacteria can adhere to a wide range of surfaces, from animal and mineral to vegetable surfaces, and that biofilms can form on various biomedical implants and devices. The biofilm glycocalyx, primarily composed of exopolysaccharides, plays a crucial role in trapping nutrients and protecting bacteria from environmental threats. The process of bacterial adhesion involves two stages: primary adhesion, which is mediated by nonspecific interactions, and secondary adhesion, which is facilitated by specific molecular interactions. The article also explores the diversity of biofilms, the resistance of biofilm bacteria to antimicrobial agents, and the architectural complexity of biofilms. It provides detailed insights into the biofilm formation of two model organisms, *Staphylococcus epidermidis* and *Pseudomonas aeruginosa*, and discusses the challenges in removing or preventing biofilms. The article concludes by advocating for the development of new testing methods that better simulate in situ conditions to predict therapeutic outcomes in biofilm infections.The article discusses the phenomenon of bacterial adhesion and biofilm formation, highlighting its ecological and evolutionary advantages. Bacteria tend to colonize surfaces rather than remain nomadic, and this behavior is advantageous for ecological interactions and survival. The article emphasizes that bacteria can adhere to a wide range of surfaces, from animal and mineral to vegetable surfaces, and that biofilms can form on various biomedical implants and devices. The biofilm glycocalyx, primarily composed of exopolysaccharides, plays a crucial role in trapping nutrients and protecting bacteria from environmental threats. The process of bacterial adhesion involves two stages: primary adhesion, which is mediated by nonspecific interactions, and secondary adhesion, which is facilitated by specific molecular interactions. The article also explores the diversity of biofilms, the resistance of biofilm bacteria to antimicrobial agents, and the architectural complexity of biofilms. It provides detailed insights into the biofilm formation of two model organisms, *Staphylococcus epidermidis* and *Pseudomonas aeruginosa*, and discusses the challenges in removing or preventing biofilms. The article concludes by advocating for the development of new testing methods that better simulate in situ conditions to predict therapeutic outcomes in biofilm infections.