Yes, when a constituent submits their form online they will see a confirmation message and they will receive a thank you email sent to the address they provided. You can customize the thank you message on the Thank You Message tab. For donation pages with recurring payment options or pay later options for memberships or events, you will see two thank you messages. You can edit these messages by clicking on the Edit Message button.
Note that if you are logged into AssociationSphere, instead of the confirmation message, you will see a message to reload the page. This allows you to enter multiple donations, memberships, or event transactions without needing to copy and paste the page URL to reload the page.