The Ethereum network measures the work behind each transaction in units called gas. Ethereum gas fees are paid in ETH, and the total depends on how much gas an action uses and on the price per unit at that moment, which climbs when the network is congested. A plain transfer needs less gas than a call to a complex contract. Wallets show an estimated fee before anything is confirmed, and on a busy day that fee can exceed a small transfer. A transaction that runs out of gas fails and still pays for the gas it used up.
Litecoin is one of the oldest coins, built on the Bitcoin design with changes that produce blocks about four times as often. On the question of Litecoin vs Bitcoin, Litecoin tends to confirm sooner and to charge lower fees, which is why some casinos accept it for deposits and withdrawals. It runs no smart contracts the way Ethereum does; its job is mainly payments. Its price swings like any unstable coin, so it suits moving value more than keeping it steady. A cashier usually states how many confirmations it waits for.