The single sign-on (Azure AD Seamless SSO) feature of Azure AD adds extra value to the Azure AD authentication process and provides a better experience for your users by eliminating the need to enter passwords or even usernames whenever you need to authenticate to Azure AD to access various resources.
Azure
Install and configure Azure AD Connect
Azure AD Connect is the replacement for DirSync and Azure AD Sync, and it in simple terms allows you to integrate your on-premises Active Directory with Azure Active Directory, keeping both directories in sync with each other. This enables you to provide identities that are consistent across your on-premises services, and services in the cloud such as Office 365, or other SaaS applications without the need for separate logon credentials to private and public cloud resources.
Authentication to NetScaler using AD FS 4.0 on Server 2016, Citrix FAS and Azure MFA in Azure Cloud
An increasing number of organisations are turning to Azure MFA to protect public and private cloud resources from intrusion by challenging users with multi-factor authentication. Azure MFA is a powerful, flexible authentication module that is either hosted in Azure Cloud itself or as an on-premises installation.