An association of persons formed for the purpose of some business or undertaking, which has a legal personality separate from that of its members. A company may be formed by charter, by special Act of Parliament or by registration under the Companies Acts. The liability of members is usually (but not always) limited by the charter, Act of Parliament or memorandum of association. A company may be a public limited company (PLC or plc), in which event its shares may be transferred freely among, and owned by, members of the public. All limited liability companies that are not public limited companies are private companies, denoted by the term Ltd. While companies are owned by their members (i.e. shareholders), they are managed by a board of directors. Historically, the duties owed by the board are fiduciary in nature and owed to the company rather than the shareholders. Companies are the major instrument for economic and financial growth and development in the Western world. A limited company encourages trade to the extent that in the event of insolvency the owners are liable only to the extent of their unpaid share capital. The limited company is a legal person in its own right and is sued in place of the owners or directors.