It does move heat from one point to another with a very low temperature rise. Although it is not strictly correct to quote thermal conductivity of a heat pipe, it is used here as a comparison to solid materials. The heat transport mechanism of a heat pipe is latent heat transport via vapor flow and not thermal conduction. Example of an electrically isolated heat pipe assembly. Heat pipes come in various sizes and styles, typically round but also in square or rectangular cross sections.
Most heat pipes used in electronic cooling are copper with water or alcohol as the working fluid.
Heat pipes with sintered wicks are the current state of the art and provide the highest heat flux density control. They also are best at returning liquid against gravity by capillary flow. Thermosiphons use buoyancy effects caused by a temperature difference in the working fluid to move heat inside a closed system. Loop heat pipes are similar to conventional heat pipes in that they use a phase change liquid to move heat. They are different in that the system forms a circulating loop with hot vapor and cooled liquid in separate lines to and from the condenser.