PEX has a lot of advantages over copper or CPVC supply lines. Its less expensive than copper and fairly easy to install. The lines are distributed from a manifold in the basement.
Each line has it's own on-off valve right at the manifold so you can turn individual lines on and off.
The tubing is flexible, so installation is fast and simple and the entire system is lead-free.
The manifold is installed vertically and looks like a fuse panel for water