Examine the role of X$-$ray crystallography in structural biology and its contributions to our understanding of molecular structures.X$-$ray crystallography is a pivotal technique in structural biology that has profoundly expanded our understanding of molecular structures. This method involves directing X$-$rays at crystallized samples of biological molecules and analyzing the diffraction patterns produced. These patterns provide detailed information about the atomic and molecular structure of the sample, allowing scientists to determine the three$-$dimensional arrangement of atoms within a molecule.