What is the difference between temperature limits and balance mode?

Temperature limits let you set temperature thresholds that trigger a response from your Smart Vents when a given limit is reached. Balance mode takes into account how you want airflow distributed throughout your home and coordinates your Smart Vents meet your needs. For example, if it is winter and you tell your Smart Vents to warm your bedroom while in balance mode, the vents in your bedroom would all open to maximize airflow, while all of the other vents in your home would close slightly to drive more air to your bedroom.