concentrate/tree top

This is going to sound stupid but I'm confused. I've always made my cider from fresh juice pressed at the mill here in town. (They just told me they would be pressing through January this year)!!I've never used tree top or the juice made from concentrate but I would like to give it a try. I've looked for tree top but can't find it. Is it a juice or a frozen concentrate that you reconstitute? Can you use frozen concentrate? Thanks

Tree Top sells frozen concentrate and re-constituted from concentrate (they may sell fresh, but I've never seen any).

I have used frozen concentrate for the base and as a gravity booster. Other people have used it for back-sweetening.

Thanks. I've used concentrate for back sweetening but didn't know if people used it for actual cider