Not everyone knows the name, but a sliding bypass door is two of two or more sliding panels that separate two spaces. This setup is often seen in a sliding bypass shower door, but you can use this type of door to separate rooms as well. Sliding bypass doors are often used in front of double closets.
A bypass door is defined by being a door that has pieces that slide horizontally, parallel to the wall but do not go inside. Anything that goes into the wall is a known as a pocket door.
These are called bypass doors because both doors are able to slide on fixed tracked. It’s the doors the are able to pass by one another in order for half of the passage to fully open. The downside of bypass doors is that they can never open 100% of the way — at least 50% of the doorway is always going to be door. Bypass doors requires tracks at the top — usually a “J” track” — and sometimes have an “E” track at the bottom but this isn’t required.