Phages, short for bacteriophages, are viruses that infect and replicate within bacteria. They are composed of a protein capsid that encloses their genetic material, which can be either DNA or RNA. Phages have a specific host range, meaning they can infect only certain types or strains of bacteria.
The life cycle of a phage typically involves attachment to the bacterial host cell, injection of their genetic material into the host, replication of phage components within the host cell, assembly of new phage particles, and finally, lysis (rupture) of the host cell to release progeny phages. Phages are abundant in various environments, including soil, water, and the human body, where they play important roles in regulating bacterial populations and influencing microbial ecosystems.