cDNA stands for Complementary DNA, which is a type of DNA molecule synthesized from an RNA template through reverse transcription process. There are several synonyms that can be used to refer to cDNA, including reverse transcribed DNA, copy DNA, and complementary DNA. Additionally, cDNA can be further classified depending on its source, such as viral cDNA, bacterial cDNA, or plant cDNA. cDNA has various applications in molecular biology, including gene cloning, gene expression studies, and DNA sequencing. Despite the availability of newer technologies in gene analysis, cDNA synthesis and amplification remains a powerful tool in genetic research and diagnostics.