As an individual, you can run a business either as a business name or as a company. A business name is issued with a certificate of registration by the Companies Registry, while a company is issued with a certificate of incorporation.
For tax purposes, a business name is not issued with a separate PIN from its owner, and as such the owner is required to file business income under one single return, eg. One tax return for employment income and business income.
For a company, it is issued with a PIN separate from the PINs issued to the company’s directors and shareholders. As such, a company, its directors and shareholders are required to each file separate and distinct tax returns on an annual basis.