how to use one arduino board to control other three arduino boards

Hi,

I would like to use one arduino board (MAIN board) to control other three arduino boards (slave board).

Each slave board has a few PWM outputs and ADC.

How can I use the MAIN board to control each PWM duty cycle of one individual slave board and also use MAIN board to collect each individual slave board's ADC value?

Currently I have arduino uno boards.

Thank you.

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