Nucleus contains DNA as a double stranded molecule .Some areas of DNA contains genes and other has gene expression.In which one strand here in coding strand and other in non coding strand.Though the coding strand is the non template strand which means not copied and on the other side the non coding strand is known as the template. The discovery of DNA Structure are copying the sequnces of nucleotides which can act as a templatefor the synthesis.
The template strand serves for a template for synthesis of a complementary RNA transcript.
Basically DNA template is a single strand of DNA that is used by the DNA polymerase enzymes as a basis of copying the DNA. Although a template is a molecule in the genetics which carries genetic code for the another molecule.