If you don't let chicken rest after cooking it leads to a loss of more flavorful juices when the chicken meat is cut.
The internal temperature of the chicken meat will always continue to rise a little during the resting period so you should remember to also remove the chicken meat from the oven or grill prior to it reaching it's target temperature for doneness.
To make the best tasting check when the chicken is finished cooking, just like a good steak, chicken needs to rest.
Once you've hit 165 degrees on the chicken, stop the heat and let the chicken rest for few minutes before cutting the chicken, so the juices redistribute themselves back through the meat.
To store cooked chicken, make sure that it does not sit out at room temperature for more than two hours or more than one hour in temperatures above 90°F.
Ensure the chicken is cooled to room temperature within two hours before stowing it in the refrigerator or freezer.
Also after chicken is cooked, the chicken must be kept hot (140°F or warmer) to prevent bacteria from growing on the chicken before you eat or store it in the fridge.
Cooked chicken should be refrigerated within no more than 2 hours after cooking or removal from an appliance keeping it warm.
Safely cooked chicken can vary in color from white to pink to tan.
All chicken meat should reach a safe minimum internal temperature of 165 °F (73.9°C) as measured with a food thermometer.
For whole chicken, check the internal temperature in the innermost part of the thigh and wing and the thickest part of the chicken breast.