With the ratification of the IEEE 802.15.3d amendment to 802.15.3, a first step has been made to standardize consumer wireless communications in the sub-THz frequency band. IEEE 802.15.3d offers switched point-to-point connectivity with data rates of 100 Gb/s and higher at distances ranging from tens of centimeters up to a few hundred meters. In this article, we provide a detailed introduction to IEEE 802.15.3d and the key design principles beyond the developed standard. We particularly describe the target applications and usage scenarios, as well as the specifics of the IEEE 802.15.3d physical and medium access layers. Later, we present the results of the initial performance evaluation of IEEE 802.15.3d wireless communications. The obtained first-order performance predictions show non-incremental benefits compared to the characteristics of the fifth generation wireless systems, thus paving the way toward the sixth generation THz networks. We conclude the article by outlining the further standardization and regulatory activities on wireless networking in the THz frequency band.