The Arbitrum bridge has the ability to send messages between the Layer-1 (Ethereum mainnet) and Layer-2 (Arbitrum network), which allows for trustless moving of assets between the two networks.
Arbitrum currently uses a centralized sequencer that is operated by Offchain Labs. It has the ability to control the ordering of transactions which could lead to the sequencer front-running transactions and profiting at the user's expense.
The Arbitrum canonical bridge is one of the safest bridges for you to transfer your crypto assets from Ethereum to Arbitrum in a simple and relatively fast manner.