IntroductionThe Covid-19 global pandemic has made the world become increasingly conscious of infectious microorganisms, and their effect on public health.  Suddenly, everyone is conscious of the surfaces they touch or encounter, the crowds they get into, and much more. Numerous products, including protective coatings, offer different types of protection, and the standard scientific terms used in those products often look interchangeably similar. For instance, many people may feel that the terms antibacterial and antimicrobial represent the same thing. It is in this context that the use of terms such as antibacterial and antimicrobial, besides others, need to be clarified and placed in context. The use of these terms has typically been in reference to antibiotics and medicines; it has been less so with respect to products that prevent infections, using protective surfaces; with the exception being disinfectants and cleaning products. Even therein, the protection offered is often transient and requires regular use of these products. There have been some pioneering approaches in this regard wherein the development of anti-fouling chemistries for uses elsewhere was envisioned to be applicable on public surfaces\cite{2018}. It is only of late, especially with the onset of the Covid-19 pandemic, that thoughts and approaches are being focused on developing smart antimicrobial coatings\cite{coatingsa}. Keeping this in mind the following write-up revisits the basics of Microbiology and places them in context with products being marketed. Some bit of background information is also worth looking into the nature and classification of products offering protection against infectious microorganisms. What does antibacterial mean?In simple terms anything that acts against bacteria is antibacterial. Bacteria are a subset of the world of microorganisms (microbes, in short) that surround us. These include viruses, algae, fungi, protists, among others. Among these pathogenic bacteria cause infections and diseases when they enter the host, which could be a plant or animal. These bacteria, then multiply and manifest themselves as infections in the hosts they have entered into. Antibacterial agents are typically designed and used for protection against pathogenic and infectious bacteria (not the rest of the microbes). Antibacterial agents are designed to counter the growth of these bacteria. The mechanisms of the actions of these agents may differ BUT they act to counter the growth and spread of bacteria in a body or any surface\cite{Neu1996}.Classification Nature of actionAntibacterials can be either Bacteriostatic OR Bactericidal. The term bacteriostatic refers to medications whose mechanism of action stalls bacterial cellular activity without directly causing bacterial death\cite{Loree2021}. In other words, the former class of agents prevents the growth of bacteria or slows their growth substantially without actually killing them directly. In reality, the demarcation between the two categories is not so sharp and distinct i.e. one that exclusively kills bacteria and another that only inhibits growth\cite{Pankey2004}.  The in vitro microbiological determination is more detailed and elaborate. This classification can be broadly applied to other agents that antifungals, antiparasitic, etc. It is a different matter, though, if there are agents that are exclusive to any of the categories of microorganisms. SourceNaturally occurring - These are naturally occurring compounds found in either plants or animals. Penicillin is a popular antibiotic that was first found and isolated from the fungus Penicillium. After this Prize-winning discovery by the scientist Alexander Fleming\cite{Fleming2001} in 1929, the world of antibiotic therapy paved way for the discovery of more such naturally occurring compounds. Plant-based alkaloids are another vast reservoir of such compounds\cite{Kaefer2011}. The history and the evolution of Tetracyclines follow another such pattern\cite{Nelson2011}.Semi-Synthetic - These are derivatives of naturally occurring compounds. Again, Penicillin is a classic example that has spawned numerous derivatives and generations of its original nature, ever since its discovery\cite{derivatives}. Another example of such antibiotics are the Macrolide class of antibiotics that are bacteriostatic antibiotics with a broad spectrum of activity against many gram-positive bacteria\cite{2002}. Development of resistance to them led to the search for the design of new semi-synthetic macrolide antibiotics\cite{Fernandes2017}.Synthetic - These are purely synthesized using in the labs and are often inspired by naturally occurring compounds that possess similar properties; the difference being knowledge of the pathways unique to microbes are taken into cognizance to make them unique in their mode of action. This approach is believed to offer a new path for the exploitation and improvement of natural products to address the growing crisis in antibiotic resistance\cite{Thaker2015}.Range of activityWhen it comes to action against bacterial growth, there are different layers of classification. Gram staining - the activity is gauged whether they are against Gram-positive AND/OR Gram-negative bacteria ( based on their Gram staining nature - a type of staining procedure to determine the nature of their cell walls). Spore-forming vs non-spore-forming - This is an important classification since certain pathogens form spores. As a result, their metabolism is different and requires different methods of arresting their growth. Aerobic vs anaerobic - Based on the nature of the bacteria to grow in an oxygen-rich and deprived environment.These are just some of the ways of classifying the range of action. Based on such layers of the classification, there are either Broad-spectrum OR Narrow-spectrum antibacterial agentsEach spectrum class has its strengths and weaknesses. Though the activity spectrum of such agents has always referred to antibiotics or medicinal compounds, protective coatings have not been often looked at from such an angle. Only a few coatings like INVESIL have been investigated as such \cite{ganesan2018}.