Why Salesforce requires Enhanced Domains?
To understand the need for this change, let’s have a look at cookies first. Not the edible cookies, but first-party and third-party cookies. Both types are bits of information that collect web-user data. Both are used to store data such as surfing and personalization preferences and user tracking information.
The difference is in who uses that data and whom the cookie collects data for.
A first-party cookie is placed on a website by the publisher or owner of the site and collects user data for the publisher or owner. They are often used to improve user experience (UX) by remembering user preferences and settings. Items added to online retail shopping carts, usernames, passwords, and language preferences are information that first-party cookies might store.
A third-party cookie is placed on a website by someone other than the owner: a third party. These could be set by an advertising network that a site may subscribe to in the hopes of collecting data and drive up sales or page hits.
As a result of regulatory and consumer pressure, major web browsers like safari, Firefox and Google Chrome are blocking third-party cookies. Today, users can choose to disable the setting to allow cookies, but browser developers indicate that they intend to permanently block third-party cookies in the future.