Drop Earrings: "These are earrings that "drop" below the earlobe just a bit. Typically, these are simple pieces where some kind of adornment like a gemstone, charm or bead drops directly from the base of the earring. These are usually fairly simple pieces and, though it hangs below the lobe, the ornamental piece is stationary or in the very least, movement is limited because it comes right off the base."
Dangle: "The word "dangle" means to hang and swing to and fro or side to side. So, a dangle earring hangs below the earlobe and has movement. The length to which they hang is varied with some that even brush the shoulders."