Lattice QCD is one of our favourite tools in theoretical physics for calculating properties of particles made from quarks and gluons. We have already learned so much about where the mass, spin, and magnetisation of particles and their resonances come from, but there is still much more that lattice QCD can do in the future while computer speeds and storage continue to improve.

In this talk, I explain why we need lattice QCD, how it works, what it can do, and briefly discuss some interesting areas of research in the field. I will also discuss my work studying the decay constants of B mesons on the lattice, relevant to flavour physics experiments like Belle II and LHCb.