In order to confirm the identity of the person entering an account, a verification code is given to a different device. It's used for two-factor authentication.
Pair
Exchange cryptocurrencies with each other, like the trading pair BTC/ETH.
Falling Knife
The term falling knife (also known as "Catching a Falling Knife" or "Catching the Bottoms") refers to the action of buying an asset which is rapidly declining in price.
Satoshi (SATS)
The smallest unit of bitcoin with a value of 0.00000001 BTC.