I have found my Fold most useful for work stuff. I can view and edit word and excel documents with plenty of space to see everything. I can do it anywhere when I have some free moments without lugging around another device. For casual stuff like Lemmy and web surfing it's just really nice to read more with less scrolling.
Others have already mentioned that this is fusion. But the fact that any nucleus with more than two protons exists at all is interesting. E=mc^2 is a well known equation, but not many people understand it's practical application. If you shove 2 protons and 2 neutrons together to form Helium, the resulting nucleus weighs less than it's constituent pieces. Where'd the lost mass go? It turned into binding energy. The energy necessary to force two positively charged protons to hang out together without flying apart. And this is part of the energy input necessary to fusion things. Conversely, when we break Uranium apart we get a lot of energy. For the same reasons. Which is how current fission reactors work.
If you really find this stuff interesting do some googling related to fission, fusion, mass defect, and binding energy.