Bacterial biofilms are an important phenomenon in microbiology. They are organized communities of microbial cells that attach to a particular surface and live within an extracellular matrix produced by the cells themselves. The bacteria within a biofilm are not simply individual cells; rather, they form organized communities and interact with one another and with their surrounding environment. Biofilm formation begins when bacterial cells approach a suitable surface and begin to attach to it. Initially, this attachment is weak and reversible, but it becomes more stable as the cells produce extracellular polymeric substances (EPS). This matrix consists of various components, including polysaccharides, proteins, and extracellular nucleic acids. It surrounds the cells and holds them together. As growth continues, small colonies develop and gradually form a more complex structure containing different regions of cells and channels that allow the movement of water, nutrients, and waste products. Cells within a biofilm exhibit physiological differences from free-living cells that exist individually in their surrounding medium. Their growth rates and metabolic activities may vary depending on their location within the biofilm. The importance of biofilms lies in their ability to increase the survival of microbial communities under various environmental conditions. They can also make some cells less susceptible to certain antimicrobial agents and disinfectants compared with free-living cells. Biofilms can form on teeth, moist surfaces, pipes, medical devices, and industrial surfaces, and they also occur naturally in aquatic environments and soil. Biofilms are particularly important in the medical field when certain microorganisms become associated with the surfaces of medical devices or tissues and continue to form microbial communities. Quorum sensing also contributes to the regulation of certain behaviors within bacterial communities, as cells use signaling molecules to communicate and coordinate their activities according to community density. Biofilms can be studied using light microscopy, confocal microscopy, and electron microscopy, in addition to microbial culture techniques and molecular methods. Therefore, biofilms represent an important field of study that connects microbiology, environmental science, public health, antimicrobial resistance, and biotechnology