In SAP, what decides the update method (synchronous/asynchronous/local), and can the user choose it?

What is transaction SM13 used for?

What is transaction SM14 (Update Program Administration) for, and what do you do after updating is auto-deactivated?

How does a logical spool server improve availability and do load balancing, and which transaction creates it?

Since a work process is not bound to one user, what mechanism preserves context between dialog steps?

When creating a custom device type, why must you not edit the SAP standard type directly, and what is the right approach?

How are locks passed between the dialog process and the update process?