There is a very important distinction between these two actions.
Redeem
When UP is redeemed, the actual UP token is removed from existence and all the native tokens that were backing that UP is returned to the person who redeemed in exchange. Recall, this redeem value goes up after every trade in proportion to the trading fees collected on every uPair on that blockchain.
Burned
When UP is only burned (without a redeem), that means the UP is removed from existence while the base tokens that were backing that UP stay within the smart contract. So now there is less UP in existence, but more base tokens in the smart contract. This means the redeem value for all remaining UP tokens (i.e. for all UP token holders) has gone up! A burn benefits everyone.
Burning vs Redeeming
