Keep raw meat, poultry, seafood, and eggs away from food that’s ready to eat.

Tools move germs around a kitchen faster than anything else. Decide in advance which board belongs to raw food.

Source: USDA FSIS, Cutting Boards and Food Safety
After raw meat or fish, run the board and knife through your dishwasher's Sanitize cycle. See How to Sanitize
The Simple Rule
Anything raw sits below anything that will be eaten without cooking. If a drip could land on it, move it up.