Bacteria are unicellular prokaryotes that dominate the biosphere at microscopic scales, and aggregates will turn them to give rise to biofilms. The biotic and abiotic stresses in their environments switch the planktonic cells to form biofilms. These biofilms are found to be beneficial and harmful to human and animal populations. The bacterial infections by biofilm formers are known to be chronic, proving to be fatal and more threatening in immunocompromised patients with debilitating diseases. Antibiotic resistance is a key attribute of bacterial biofilms that tolerate multiple drugs that worsen the health of patients with medical dwelling units. The mechanism of biofilm formation is less or more common with reversible and irreversible events of attachment and adhesion followed by aggregation to form mature biofilm. The biofilm is a resultant of cyclic di-guanosine monophosphate (C-di-GMP) that orchestrates the composition of extracellular polymeric substances. The resource limitation in the biofilm ends the aggregation with the release of planktonic cells and pioneer new biofilm. There are several medical units and natural habitats enriched with biofilms that could be causing benefits and huge losses. The genetics of biofilm formation showed that ica operon was associated with the accumulation of polymeric matrix. The studies on biofilm control with the role of gene expression contributed to reducing the burden of antibiotic-resistant forms. The chapter encompasses the available information on bacterial films from different aspects with their impact on human lifestyle.