DNA replication and DNA transcription are two different processes that occur in a cell. DNA replication is the process of making more copies of DNA. This process is done in the preparation of cell division. At the beginning of DNA replication, the unwinding of the double helix is done by DNA helicase, and DNA polymerase moves along the strands to bind complementary nucleotides.
At the end of the process, the result is two exact copies of DNA double helices. DNA transcription is the process of copying DNA to produce RNA. A portion of DNA that codes for a specific gene is transcribed to mRNA.
At the beginning of the process, the unwinding of the double helix is done by DNA helicase, and RNA polymerase moves along the strands to bind complementary nucleotides. At the end of the process, mRNA is produced. mRNA serves as the blueprint for translation (protein synthesis), which takes place in the ribosome.