From Thelemapediapentagram represents the microcosm, the hexagram can be said to represent the macrocosm. Its six points are accorded to the planetary bodies of Saturn, Jupiter, Mars, Sol, Venus, Mercury, and Luna. These in turn are related to six Sephiroth of the Tree of Life, as can be seen when aligning the Hexagram with the Central Pillar. If the Lesser Ritual of the Pentagram is elemental magick, then the Lesser Ritual of the Hexagram involves planetary magick.
Though it's often regarded as macrocosmic, closer inspection reveals that the hexagram is the union of elemental glyphs for Fire and Water and, as such, is also a symbol of the Great Work - the union of opposites. The symbol can be further analyzed to reveal the glyphs of Earth and Air as well, indicating that it's not simply macrocosmic, but includes the microcosm as well. From this it can be seen that the Hexagram is similar to the Rosy Cross.
Aleister Crowley searched for a means to create a hexagram composed of one single, continuous line, as opposed to the dual triangles in the traditional form. His efforts led to the unicursal hexagram, which further codifies the symbolism contained within the hexagram, the rosy cross, and the ankh.