What is the difference between transfection and transduction?

Transfection is the introduction of nucleic acids into eukaryotic cells using non-viral methods. Common techniques include lipofection (lipid-mediated), calcium phosphate precipitation, electroporation, and microinjection. It can be transient (temporary expression) or stable (integration into genome). Transduction uses viral vectors (lentivirus, adenovirus, AAV) to deliver genetic material. Transduction typically achieves higher efficiency, especially in difficult cells, and can infect non-dividing cells. Selection depends on cell type, efficiency requirements, desired expression duration, and safety considerations.