Transduction is a DNA transfer mediated by bacteriophage. The DNA transfer occurs after the bacteriophage infects a donor bacteria and carry parts of that bacteria's DNA into a new recipient bacteria cell. Not all virus can perform transduction and not all bacteria are transduceable.

Figure 1.广义传导
Bacteriophage transfers the DNA either in generalized or in specialized ways. The difference is in the parts of donor bacteria that are transferred. In generalized, any portion of donor's genome is carried by the virus. In specialized, DNA from a specific region of the host chromosome is integrated directly into the virus genome.