Here's why:

* Sequencing directly determines the order of nucleotide bases (A, T, C, G) in a DNA strand. This provides the most fundamental and detailed information about the DNA molecule.

* Other techniques like PCR (polymerase chain reaction), gel electrophoresis, and restriction enzyme digestion are often used as preparatory steps before sequencing or for other purposes like identifying specific DNA fragments.

Let me know if you'd like to know more about any of these methods!