What is the difference between a template and a primer?

A template is DNA that contains the target that you want to amplify, where target refers to the specific region of DNA. A primer is a short, single-stranded synthetic DNA molecule whose sequence corresponds to a region adjoining the target you are trying to amplify. It provides a starting point for DNA synthesis. The enzyme that synthesizes DNA, DNA polymerase, can only add nucleotides to an already existing strand or primer of DNA or RNA that is base paired with the template.