What is "ionic technology" and why is it in all the new hair tools?

Ions are molecules with a positive or negative charge. Negative ions are beneficial in blow dryers and other styling tools for several reasons: they help to quickly break up water molecules, reducing drying time; they help close the hair cuticle, sealing moisture into the hair shaft while locking out humidity and frizz; and they leave hair revitalized, soft and silky.