The terahertz (THz) frequency band is positioned between electronic and optical frequencies in the frequency spectrum. This particular band has many applications but adapting the technologies for THz band is quite difficult due to the absent of a suitable waveguide for THz frequencies. So far, researchers have suggested many metallic and dielectric waveguides to solve this problem. Specially, in recent years, different porous core waveguide structures for the terahertz (THz) propagation have been proposed by various researchers worldwide. These porous core waveguides use dielectric materials as their fiber host and their design parameters are tuned to introduce versatile guiding properties for the THz propagation.