A simple and efficient way to obtain insights into the mechanisms controlling how materials perform can be obtained by designing molecular dynamics simulations. It is mainly aimed at predicting the positions of atoms versus time. These positions are derived from the forces exerted by the neighboring atoms on one given atom. To obtain molecules and not only atoms, covalent bonds but also Valence angles and dihedral angles are usually modeled by springs whereas the intermolecular forces, mainly Van der Waals and Coulombic forces, are modeled by Lennard-Jones and point charge potentials respectively. For example, the way carbon nanotubes operate at the surface of carbon fibers or in epoxy matrix can be investigated by molecular dynamics simulations. We apply this apparently simple simulation technique to predict a plethora of mechanical, physical, and chemical properties for a vast range of materials like carbon nanotubes, graphene, carbohydrates, inorganic and organic polymers, metals, ice, etc.