PAYE is how most employees' income tax is collected: rather than paying a lump sum at year end, tax is deducted from each salary by the employer and paid to SARS. This keeps the employee roughly up to date on their tax throughout the year.
UIF is a separate contribution that funds benefits for workers who become unemployed or cannot work for certain reasons, such as illness or maternity. Both the employer and the employee contribute, and the employer pays the combined amount over.
Employers typically calculate, deduct and remit PAYE and UIF monthly, and report them to the authorities. Exact rates and rules are set by SARS and the relevant funds — confirm current requirements with a payroll professional or SARS.