Embedded Login is another option for customers who want to authenticate their users through Salesforce, but their website doesn’t support user authentication through SAML or OpenID Connect.
To add Embedded Login to your websites, create your community with your desired branding. Then configure identity providers, such as Facebook, Twitter, Instagram, Google, Amazon, or PayPal.
When the community is set up, web developers can add a login form to any web page on your site. Visitors log in using their credentials from any identity provider that you configured for your community.
Salesforce handles the login, brokering protocol with social sign-on providers and SAML identity providers, and integration with Salesforce. Meanwhile, your web developers determine the customer experience. For example, they can customize the styling on the login form and personalize their users’ experience with information retrieved from the login process.