Antibiotics (From ancient Greek αντιβιοτικά, antiviotika) also called antibacterials, are a type of antimicrobial drug used in the treatment and prevention of bacterial infections. They may either kill or inhibit the growth of bacteria. No antibiotics possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics.
Sometimes the term antibiotic (which means "opposing life") is used to refer to any substance used against microbes, synonymous with antimicrobial. Some sources distinguish between antibacterial and antibiotic; antibacterials are used in soaps and disinfectants, while antibiotics are used as medicine.
Antibiotics revolutionized medicine in the 20th century. Together with vaccination, antibiotics have led to the near eradication of diseases such as tuberculosis in the developed world. However, their effectiveness and easy access have also led to their overuse, prompting bacteria to develop resistance. This has led to widespread problems, so much as to prompt the World Health Organization to classify antimicrobial resistance as a "serious threat [that] is no longer a prediction for the future, it is happening right now in every region of the world and has the potential to affect anyone, of any age, in any country"....LESS