This is a review article discussing the latest developments in beam-steering antennas at millimeter-wave frequencies for Beyond-5G and 6G networks. This article classifies all the beam-steering techniques described in the literature in four categories, namely, phased arrays, quasi-optical systems, leaky-wave antennas, and metasurfaces. An overview of the four classifications is presented with a detailed comparison outlining the state-of-the-art and limitations of different technologies.