Normal flora refers to the collection of microorganisms that live on or within the human body without causing disease. These organisms are critical to maintaining a healthy microbial balance that supports numerous bodily functions, such as digestion, protection against pathogens, and the production of vitamins. There are several synonyms for normal flora that may be used interchangeably, such as commensal bacteria, microbiota, or resident flora. These terms describe the normal microbial population found in different areas of the body, including the gut, skin, and mouth. Understanding the diversity and characteristics of normal flora is essential for developing treatments for infections and disease prevention strategies that preserve this vital component of human health.