So from what I understood from some coure notes I've been reading, a microcanonical ensemble is a situation where we have an isolated system in thermal equilibrium with a constant given N,V,E - particles, volume,total energy. I'm a bit confused. How I understood 'ensemble' is as a set of all the allowed microstates for a certain macrostate. This makes sense for distinguishable systems like a lattice, but makes no sense to me for an indistinguishable system like a gas. Can someone explain to me what the difference is between distinguishable and indistinguishable systems is within this ensemble?