Here's a breakdown:

1. DNA as the template: Transcription starts with DNA, which contains the genetic code for making proteins. A specific segment of DNA, called a gene, is used as the template for making mRNA.

2. RNA polymerase enzyme: An enzyme called RNA polymerase binds to the gene and unwinds the DNA double helix.

3. RNA nucleotides: RNA polymerase then reads the DNA sequence and uses it to assemble a complementary RNA molecule. Instead of thymine (T), RNA uses uracil (U).

4. mRNA strand: This newly synthesized RNA molecule, now called messenger RNA (mRNA), carries the genetic code from the DNA to the ribosomes, where protein synthesis takes place.

5. Processing: The newly made mRNA molecule often undergoes further processing, including capping and polyadenylation, before leaving the nucleus to be translated.

So, to summarize, transcription is the process of using DNA as a template to create a complementary mRNA molecule. This mRNA then carries the genetic information to the ribosomes for protein synthesis.