Transaction Lifecycle
The easiest way to understand the full system is to follow transactions that touch settlement, the gate app, and application execution environments.
Deposits
Deposits go through the bridge first. The bridge records the asset movement, the gate app receives the deposit event, and the gate routes the asset to the target app.

Withdrawals
Withdrawals start in the target app. The app sends the withdrawal to the gate, and the gate forwards it to settlement during the next settlement update.

Cross-app transfers
Cross-app transfers are composed of app-level messages. The source app sends a transfer to the gate or destination app, and the destination app credits the user once the ordered message is processed.

The important property is that most work stays inside the execution network. Settlement is used for security, data availability, and bridge effects rather than every internal app action.