Graphene plasmonics has shown rapid progress due to graphene's unique electrical and optical properties, tunability, and long-lived collective excitation. This review discusses the basic properties of graphene plasmons, including their energy dispersion, localization, propagation, hybridization with phonons, and damping mechanisms. The terahertz to mid-infrared regime is a technologically significant but underexplored area for graphene plasmonics, with potential applications in modulators, filters, photodetectors, and spectroscopy. Graphene's tunable optical properties, high carrier mobility, and compatibility with silicon photonic platforms make it a promising material for plasmonic devices. Graphene plasmons, which are collective electron excitations, enable tunable plasmonic devices with extreme light confinement, making graphene an attractive platform for nanophotonics in the terahertz to mid-infrared range. The plasmon dispersion in graphene is described by the equation $ \omega_{pl} \propto \sqrt{q} $, where $ q $ is the wave vector. This dispersion is influenced by factors such as doping and the substrate. Plasmon-phonon hybridization can lead to modified plasmonic dispersion and enhanced optical absorption. The damping of plasmons occurs through various mechanisms, including Landau damping, radiative processes, and inelastic scattering with optical phonons. Graphene plasmons can be manipulated using external fields, such as magnetic fields, which can split plasmon resonances into multiple peaks and affect the plasmon lifetime. The application of magnetic fields can also tune the energy and lifetime of plasmons in graphene, enabling the development of tunable optoelectronic devices. Graphene-based metamaterials offer a wide design space for functional devices, including tunable filters, shields, and polarizers. These devices can operate in the terahertz to mid-infrared range and are compatible with standard silicon processing technologies. Graphene plasmonics has the potential to enable compact, efficient, and tunable devices for applications in imaging, sensing, and communication. The use of graphene plasmonics in vibrational spectroscopy has shown promise for enhancing optical fields and improving the detection of molecular structures. Plasmonic effects can enhance Raman scattering and second harmonic generation, enabling the study of molecular vibrations at the nanoscale. The combination of graphene's unique properties with plasmonic effects opens up new possibilities for advanced spectroscopic techniques and nanoscale sensing applications.Graphene plasmonics has shown rapid progress due to graphene's unique electrical and optical properties, tunability, and long-lived collective excitation. This review discusses the basic properties of graphene plasmons, including their energy dispersion, localization, propagation, hybridization with phonons, and damping mechanisms. The terahertz to mid-infrared regime is a technologically significant but underexplored area for graphene plasmonics, with potential applications in modulators, filters, photodetectors, and spectroscopy. Graphene's tunable optical properties, high carrier mobility, and compatibility with silicon photonic platforms make it a promising material for plasmonic devices. Graphene plasmons, which are collective electron excitations, enable tunable plasmonic devices with extreme light confinement, making graphene an attractive platform for nanophotonics in the terahertz to mid-infrared range. The plasmon dispersion in graphene is described by the equation $ \omega_{pl} \propto \sqrt{q} $, where $ q $ is the wave vector. This dispersion is influenced by factors such as doping and the substrate. Plasmon-phonon hybridization can lead to modified plasmonic dispersion and enhanced optical absorption. The damping of plasmons occurs through various mechanisms, including Landau damping, radiative processes, and inelastic scattering with optical phonons. Graphene plasmons can be manipulated using external fields, such as magnetic fields, which can split plasmon resonances into multiple peaks and affect the plasmon lifetime. The application of magnetic fields can also tune the energy and lifetime of plasmons in graphene, enabling the development of tunable optoelectronic devices. Graphene-based metamaterials offer a wide design space for functional devices, including tunable filters, shields, and polarizers. These devices can operate in the terahertz to mid-infrared range and are compatible with standard silicon processing technologies. Graphene plasmonics has the potential to enable compact, efficient, and tunable devices for applications in imaging, sensing, and communication. The use of graphene plasmonics in vibrational spectroscopy has shown promise for enhancing optical fields and improving the detection of molecular structures. Plasmonic effects can enhance Raman scattering and second harmonic generation, enabling the study of molecular vibrations at the nanoscale. The combination of graphene's unique properties with plasmonic effects opens up new possibilities for advanced spectroscopic techniques and nanoscale sensing applications.