What is the name of microorganisms which reproduce only inside the living cells of other organisms?

Viruses are unique microorganisms that can only reproduce inside the living cells of other organisms. Unlike bacteria and other microbes, viruses are not considered fully alive because they cannot carry out life processes independently. They consist of genetic material (DNA or RNA) wrapped in a protein coat and lack the cellular machinery needed for reproduction. When a virus infects a host cell, it hijacks the cell's mechanisms to make copies of itself, often destroying the host cell in the process. This dependency on living cells makes viruses obligate parasites. Common viral infections include the common cold, influenza, measles, chickenpox, and more serious diseases like HIV/AIDS and hepatitis. Understanding viral reproduction is crucial for developing antiviral medications and vaccines.