Boost - Nuclear weapons of this kind use fissionable material plus deuterium or tritium in very small amounts, this helps to increase nuclear material burning and as a result explosion yield is increased more than two times.
Deuterium - Stable, natural Hydrogen isotope. Formula - D2. Heavy form of Hydrogen. The nuclei consists of 1 proton and 1 neutron. Combined with Oxygen it forms Heavy Water. Used in moderate fission reactions.
Fission [reaction] - Splitting of an atom into two or more parts. Accomplished by bombarding fissionable nuclei with neutrons, which in turn causes nuclei to fly apart releasing large amount of energy. Materials used - U235 or Pu239 isotops, elements produced - Iodine131, Caesium137, Strontium90, Barium143 and Krypton90.
Fusion [bomb] - Actually this is Fission/Fusion type reaction, initially the fission type device is detonated, that produces enough heat to start the thermonuclear (fusion) reaction, the yield is theoretically unlimited. Fusion material is Hydrogen, practically Lithium-6 Deutride ("Dry Bomb") is being used instead of Hydrogen, due to size & some other technical problems.
Fusion [reaction] - Binding together of hydrogen atoms, creating helium.
Heavy Water - Chemical composition identical with regular(light) water - H20. However hydrogen is replaced with Deuterium(see above) which has extra neutron. Hence the name, heavy water and formula D20
Tritium - Relatively rare Hydrogen isotope. The nuclei consists of 1 proton and 2 neutrons. Tritium is radioactive, and has half-life period of 12.3 years. Decays into a low energy beta particle with an average energy of 5.7 keV. Naturally there is only approx. 10kg of Tritium in the world. However Tritium can be artificially produced by bombarding Lithium nucleus with high energy protons.