[particlewave]

All innards are identical. All that varies is the number of plates per cell, plate weight(amount of lead oxide per plate), and plate size. Specs are based on these factors, so for example, an Everstart 760CCA 94R group battery would have the exact same innards as a Duralast 760CCA 94R group. Of course, AGM (spiral wound included) is a different story
Spiral wound: Instead of many separate plates bound together in each cell by a cast-on strap, a spiral wound battery uses two plates only (one positive, one negative) that are long strips of lead wound into a coil and separated by an absorbent glass mat separator(nasty stuff to work with). Six of these coils at 2V each are joined together like a six pack to make a 12V battery. One advantage is the lower chance of shorts within a cell because of fewer parts. Shorts are a huge manufacturing problem.

It's funny to watch arguments about Duralast vs Everstart on other forums when I know that they are exactly the same.