Non-concessional contributions are contributions made with your post-tax income. You have already paid taxes on those earnings so no further tax applies when you add them to super, provided you don't pay more than the non-concessional contributions limit.
Personal contributions you make to your super from your take-home pay. Your employer may pay these on your behalf through a payroll deduction arrangement or you pay directly to your super account.
You cannot make voluntary contributions if you have not provided your Tax File Number (TFN) to your super fund.
Voluntary contributions you make to your spouse's super. If your spouse is on a low annual income, you may be eligible for a tax offset. These contributions count toward your non-concessional cap.
A government contribution to your super if you're on a low to middle-income and make voluntary contributions to your super in a financial year.