An ITR14 or Income Tax Return is a form that SARS requires all companies registered with CIPC to complete and submit to SARS once every year. The form is used to declare your incomes and expenses/deductions so that SARS can calculate how much tax your business need to pay, or how much of a tax refund SARS needs to pay to you.
If you run a business that is not registered with CIPC, you would enter in your business-related incomes and expenses into your personal ITR12 tax return, under the Local Business section.