What is a Secondary Dwelling? Definition or Meaning

‘Secondary Dwelling’ definition: The following definition is taken from the Standard Instrument – Principal Local Environmental Plan. Secondary dwelling means a self-contained dwelling that:
(a)  is established in conjunction with another dwelling (the principal dwelling), and (b)  is on the same lot of land as the principal dwelling, and (c)  is located within, or is attached to, or is separate from, the principal dwelling.
Secondary dwellings are a type of residential accommodation—see the definition of that term.