A pathogen is a microorganism that infects its host and causes sickness. Viruses, bacteria, protists, and fungi are all pathogens. The infection then replicates in the host body before departing and spread to a new host. Pathogens can be spread in a variety of ways, including skin contact, body fluids, and contact with infected surfaces. Some diseases can be detected in the form of airborne particles.

A virion is not the same as a virus. It's nothing more than a virus in its extracellular phase. Additionally, it is a fully functional viral molecule made up of DNA or RNA. It is also surrounded by an external protein shell known as a capsid. These virions are typically spherical or rod-shaped entities.

An antibiotic is a kind of antimicrobial drugs that prevents bacterial growth. These drugs are frequently used to treat and stop infections of all kinds. These prevent the production of enzymes needed for protein or nucleic acid processing. They also affect microorganisms by rupturing their cell walls or membranes. In 1943, the microbiologist Selman Waksman discovered streptomycin and came up with the word "antibiotics." The two antibiotics that are utilised to treat any infections are streptomycin and penicillin.