Ultrafast spin dynamics plays a pivotal role in photoinduced THz emission due to the sub-picosecond timescale of magnetoelectric interactions, which aligns with the THz frequency range. This study explores THz absorption and emission dynamics across ferromagnetic structures, ranging from single-metallic layers to multilayers with interfacial effects. The observed THz emission dynamics stem from ultrafast spin-related phenomena such as the inverse spin Hall effect, inverse Rashba-Edelstein effect, and inverse spin-orbit torque. We investigated the influence of interfaces, incorporating factors like THz wave reflection and attenuation, estimating THz emission contributions from individual interfaces. Comprehensive analysis provides new insights into mechanisms governing THz emission involved with ultrafast spintronic processes in ferromagnetic multilayers.