Copyright is a property right that exists in original literary, dramatic, artistic and musical works.
Like the name suggests, copyright laws protect against unauthorised copying of a copyright work. Copyright does not protect the idea embodied in a copyright work, only the way in which that idea has been expressed.
Under NZ copyright law "original" means not copied from anything else. Another way of expressing this is that the work must be the product of the author's own time, labour, skill and judgment.