Deposit is to put assets into layer 2 for cross-chain transactions. Assets deposited to L2 are not distinguished by their original chains. That is what we call aggregated assets. In Zecrey, the concept of chain no longer exists in L2. The zk-rollup based L2 performs off-chain calculation with complex zk-proof, and verifies the process on L1 chains, with its security rooted in L1.