Transcription and reverse transcription differ in the template, the enzymes involved, the product and their function.
Template: Transcription is the process in which a segment of DNA is copied into mRNA. Therefore, transcription uses DNA molecules as templates. In contrast, reverse transcription synthesizes cDNA with RNA as template.
Enzymes involved: Transcription involves the application of RNA polymerase, while in reverse transcription, reverse transcriptase is involved.
Product: The end product of transcription is mRNA, whereas for reverse transcription, the product is complementary DNA (cDNA).
Function: The function of transcription is to synthesize a mRNA molecule that has the same genetic information of the coding strand of DNA, which can later be translated into a functional protein. However, reverse transcription is used by retroviruses to incorporate their genes into the hose genome. It is often employed in research to identify the coding sequences of DNA and to prepare cDNA libraries.