The Index consists of liquid United States dollar-denominated, high yield corporate bonds for sale in the United States, as determined by International Index Company Limited. HTG is based in Boston, MA.
In direct current (DC), the electric charge (current) only flows in one direction. Electric charge in alternating current (AC), on the other hand, changes direction periodically. The voltage in AC circuits also periodically reverses because the current changes direction. Most of the digital electronics that you build will use DC.
Direct current is the type of current that comes from a solar cell or battery. The positive and negative terminals of these power sources never change, so the current runs in the same direction the entire time. Direct current does not allow for power to be efficiently transported over large distances.