Aromaticity:A property of cyclic, planar structures with delocalized π-electrons following the $(4n + 2)$ rule, which leads to enhanced stability.
Conjugation:The overlap of p-orbitals across adjacent single and multiple bonds leading to delocalized electrons in a molecule.
Molecular Orbitals: Orbitals resulting from the combination of atomic orbitals when atoms bond, describing regions in a molecule where electrons are likely found.