Looks like a Pex piping and Sharkbite fitting installation to me. Pex is pretty freeze friendly, unlike copper it will expand vs burst when freezing. Pex has some advantages and disadvantages over copper. Generally speaking, if you live in a winter freeze area and have exposed or easy access piping in the basement or crawl space you might want to use Pex, or if you have water lines inside an exterior wall.
It’s cheaper to install, very easy to fix or replace and protects against uninsulated space and pipe freeze concerns. I wouldn’t use it in difficult areas to access (inside of interior walls or under floors or concrete slab) because the life expectancy is about half that of copper. The jury is still out on the effects of micro plastics on human health, so if your concerned about that then you should stick to copper.
I do find the elbow terminating at a floor joist puzzling. Not a normal or recommended penetration point at all, and not a standard method of bracing. Looks like someone was being paid by the hour to install pipe. It does offer a great dead leg situation for debris and crud to build up in, not a good piping technique.