what means transduction explain briefly with example

Transduction is the process through which DNA is transferred from one bacterium to another by virus. The bacteriophages function as vector to transfer DNA from donor bacteria into recipient bacteria. The transfer of bacterial genes by phage was discovered by Lederberg and Zinder in 1951 in Salmonella typhimurium. There are two types of transduction : - 

• Generalized transduction : In this type of transduction each part of the bacterial genome has approximately the same probability of being transfered from donor to recipient bacteria.
• Specialized transduction : It is mediated only by specific temperate phages, and only a few specific donor genes can be transferred to recipient bacteria.