Biosafety labs are specialized facilities designed to safely study infectious materials and biological agents, classified into four levels (BSL-1 to BSL-4) based on the risk they pose. BSL-1 labs handle low-risk agents, while BSL-4 labs deal with highly infectious and dangerous pathogens, employing strict safety precautions. Each level has specific requirements for safety protocols, personnel training, and lab design to ensure security and containment.