A network fee is a charge for processing a transaction on the blockchain network (for example, TRC-20) — it’s not a fee charged by Zorion. When you send USDT, the transaction needs to be processed and confirmed by network participants (validators), and the network fee is the reward for that work, distributed across the network rather than going to Zorion. The fee amount depends on how busy the network currently is: the more people are transacting at a given moment, the higher the fee can be, and vice versa. This is standard practice across all blockchains and crypto wallets, not something unique to Zorion.