  In this study we have investigated a particular state-of-the-art model which
is currently used to refine our knowledge of the workings of the strong
interaction and the way that it is manifested in both neutron stars and heavy
nuclei, although we have placed emphasis on the former for reasons of personal
interest. The main body of this work has surrounded an effective field theory
known as Quantum Hadrodynamics (QHD) and its variations, as well as an
extension to this known as the Quark-Meson Coupling (QMC) model, and variations
thereof. We further extend these frameworks to include the possibility of a
phase transition from hadronic matter to deconfined quark matter to produce
hybrid stars, using various models. We have investigated these pre-existing
models to deeply understand how they are justified, and given this information,
we have expanded them to incorporate a modern understanding of how the strong
interaction is manifest.
