From the IRS web-site "Limited Liability Company (LLC)
A Limited Liability Company (LLC) is a business structure allowed by state statute. LLCs are popular because, similar to a corporation, owners have limited personal liability for the debts and actions of the LLC. Other features of LLCs are more like a partnership, providing management flexibility and the benefit of pass-through taxation.
Owners of an LLC are called members. Since most states do not restrict ownership, members may include individuals, corporations, other LLCs and foreign entities. There is no maximum number of members. Most states also permit â€œsingle memberâ€ LLCs, those having only one owner.
A few types of businesses generally cannot be LLCs, such as banks and insurance companies. Check your stateâ€™s requirements and the federal tax regulations for further information. There are special rules for foreign LLCs."