What is Layer 2 Deposit?

A layer 2 deposit is a crypto deposit sent over a network that settles on top of a base chain rather than on the chain itself. Arbitrum, Base, Optimism and Polygon are the common ones for Ethereum; the appeal is that a transfer costs cents rather than several units of currency and confirms in seconds. The reason it matters to a depositor is not cost but risk of loss. The same asset exists on several networks with the same ticker and often the same address format, so a deposit page asking for USDT gives no clue by itself about which network it expects. Sending layer 2 funds to an address the casino only monitors on the base chain produces a transaction that succeeds on the network and never arrives in the account, and recovery depends entirely on whether the operator controls that address on the other network too. The practical rule is that the network is part of the address, not a detail beside it. Choose the network on the withdrawal side to match exactly what the cashier displayed, send a small test amount the first time with a new operator, and treat any deposit page that lists a ticker without naming a network as incomplete rather than flexible.