No problem joe! Join can be used when you have individual surfaces that have edges touching each other. Join glues individual surfaces like that into a connected piece.

The booleans on the other hand work with solids and will intersect the pieces with each other, slicing some pieces out and then connecting them up into a new combined solid.

So if you have a bunch of surfaces you want to glue together, Join works for that, if you have solids pushing through each other use booleans for that case instead.

- Michael