Reverse transcription is the process in which an mRNA molecule is used as a template to generate a strand of DNA, called complementary DNA or cDNA. Each nucleotide in the cDNA strand is produced based off its complement in the mRNA strand, so that the process literally works in "reverse" of normal transcription, which converts DNA into RNA. As such, reverse transcription violates Crick's central dogma of molecular biology.
Reverse transcription appears in a variety of contexts; for example, it is integral for the replication of retroviruses like HIV.
