HHO gas is used as the short or slang term for oxyhydrogen among the online community. Many online videos use the term HHO when demonstrating their electrolysis devices for improving car performance.
HHO gas is the product of electrolysis on H2O or pure water. Two individual hydrogen atoms and one oxygen atom. The actual chemical composition is H2 H2 O2. As each water molecule consists of two hydrogen and one oxygen atom two water molecules are required to complete the formula. The O1 from the first atom is an unstable free radical which reacts with the second oxygen atom from molecule two to form dioxygen, O2. The most common name of HHO gas is oxyhydrogen.
Electrolysis: 2 H2O → 2 H2 + O2
Source: http://en.wikipedia.org/wiki/HHO
