  It is possible that primordial black holes consitute (or consituted) a
significant fraction of the energy budget of our universe. Terrestrial
gravitational wave detectors offer the opportunity to test the existence of
primordial black holes in two different mass ranges, from $10^2\,{\rm
g}-10^{16}\,{\rm g}$ to $10^{-6}\,M_\odot-100 \,M_\odot$. The first mass window
is open via induced gravitational waves and the second one by gravitational
waves from binary mergers. In this review, we outline and explain the different
gravitational wave signatures of primordial black holes that may be probed by
terrestrial gravitational wave detectors, such as the current LIGO/Virgo/KAGRA
and future ones like Einstein Telescope and Cosmic Explorer. We provide rough
estimates for the frequency and amplitude of the associated GW background
signals. We also discuss complementary probes for these primordial black hole
mass ranges.
