Bacterial adhesion is the process by which bacteria attach themselves to surfaces, including host tissues, medical devices, and natural environments. This attachment is often facilitated by structures such as fimbriae and pili, which help bacteria stick to surfaces and each other. Adhesion is a critical first step in the formation of biofilms, which are communities of bacteria that can be resistant to antibiotics and immune responses. Once adhered, bacteria can begin to multiply and establish colonies. This can lead to infections in humans and animals, as well as contribute to the deterioration of materials. Understanding bacterial adhesion is essential for developing strategies to prevent infections and manage biofilm-related issues in various settings, including healthcare and industry.