In this study, the sorption and desorption isotherms from the dynamic vapor sorption test are modeled by using six different models, that is, the (i) BET (Brunauer–Emmett–Teller), (ii) modified BET, (iii) GAB (Guggenheim–Anderson–Boer), (iv) PEK (parallel exponential kinetics), (v) HH (Hailwood–Horrobin), and (vi) Nelson and Young models. The application principle of each model is explained and a comparison is done between these models, based on the understanding of sorption mechanisms on or into the textile substrates. They mainly depend on the chemical nature of the fibers used to manufacture the samples. Thus, the presence of various sorption/desorption sites on the surface and/or in the inner core of hydrophilic materials promotes the formation of more hydrogen bonds with water vapor molecules than for hydrophobic materials. Among these previous used models, the PEK, HH, and Nelson and Young models were studied to analyze the water molecule diffusion into the structures, while the GAB and BET models were selected to gain information on the water uptaken as the monolayer and energies of interactions between fibers and water molecules. By understanding the hydric behavior of fabrics during sorption/desorption processes, the fiber blends can be modified for improving the wearer comfort.