A Series Limited Liability Company is a master LLC whose organizing document provides for separate subunits (series), which operate as independent LLCs. It is a form of a limited liability company that provides liability protection across multiple “series” each of which is theoretically protected from liabilities arising from the other series, protect personal assets from a legal claim relating to their real estate investment or business liabilities. Additional liability protection may be gained by properly forming and maintaining a separate LLC to hold each property or business entity. By forming a separate LLC to own and hold each legally titled separate property or business entity, theoretically only the assets owned by a specific LLC would be subject to claims or lawsuits arising against that LLC. Under Delaware law, a series can enter into contracts, hold title to assets, grant liens and security interests and sue or be sued.
Read more: https://en.wikipedia.org/wiki/Series_LLC