Example of MIR and FIR spectra of galaxies. The spectra at these wavelengths contain a plethora of features useful for deriving SFR, BHAR and metallicity. The observed wavelengths of some of these tracers are reported in the figure, together with the SED of an example star-forming galaxy at z = 0, z = 2, and z = 4 taken from Moullet et al. (2023, Section 47). We also highlight the wavelength coverage of JWST, PRIMA (shaded region), and ALMA.