How do Sender Profile and Delivery Profile settings work in Marketing Cloud?

Sender Profile: Defines the identity of the sender as seen by the recipient:
— From Name (display name in inbox)
— From Email Address (must be an authenticated domain with SAP)
— Reply-to Email Address (optional override; used with RMM)
Multiple sender profiles can exist per BU for different brands, products, or sub-brands. Profiles can be locked at the parent BU so child BUs cannot change the From address.
Delivery Profile: Defines the infrastructure and compliance settings for the send:
— Physical mailing address (required by CAN-SPAM)
— IP address or IP pool to use for sending
— Header/footer content (can include standard unsubscribe links)
— Encoding
Both are combined in a Send Classification. When creating an email send, the send classification (or individually selected sender/delivery profiles) determines how the message is authenticated, which IP it comes from, and what compliance elements are included.