What is the difference between Delegations and Shared Mailboxes?

The difference between Delegations and Shared Mailboxes is as follows:

Shared Mailboxes:

A shared mailbox is a mailbox that multiple users can use to read and send email messages. Shared mailboxes make it easy for a specific group of people to monitor and send email from a common account, like public email addresses (for example, info@unsw.edu.au or student.services@unsw.edu.au). When a person in the group replies to a message sent to the shared mailbox, the email appears to be from the shared mailbox, not from the individual user. Creation and management of a shared mailbox is done by UNSW IT upon request from customers. A shared mailbox appears as an added account in Outlook profile.

Delegations:

Email delegation is where someone has allowed you to access their mailbox to receive and respond to e-mail messages and meeting requests and responses on their behalf. As a delegate, you may have also be granted additional permissions that allows you to read, create, or have more control over items to that mailbox. Delegation is done by the owner of mailbox using Microsoft Outlook email client.