system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: The difference between an nuclear bomb and a hydrogen bomb.
gpt
A hydrogen bomb is a kind of nuclear bomb. Specifically one that uses nuclear fusion to boost the yield (explosive power) of the bomb.

The first nuclear weapons used purely nuclear fission (splitting an atom) to produce energy. That gives you a huge bang, but it's pretty inefficient since most of your fuel just gets blasted apart instead of fissioning to make the big boom.

Second-generation bombs introduced a second stage with a different kind of fuel that allowed for fusion (smooshing two atoms into one bigger atom). The fusion stage takes the energy from the fission, and uses it to fuse lightweight atoms into heavier ones, which releases crazy amounts of energy. This makes your bomb much more efficient, which means you get a bigger boom from a smaller bomb.