Bacteriophages, often called phages, are viruses that specifically infect and replicate within bacteria. They are composed of genetic material, either DNA or RNA, surrounded by a protein coat. Phages attach to bacterial cells, inject their genetic material, and hijack the bacterial machinery to produce new phage particles, ultimately leading to the destruction of the bacterial cell. These viruses are found in various environments, including soil, water, and the human gut. Bacteriophages are being researched for their potential use in treating bacterial infections, especially in cases where antibiotics are ineffective, making them a promising tool in the fight against antibiotic resistance.