Azure AD Connect
Azure AD Connect is a tool for connecting on-premises identity infrastructure to Microsoft Azure AD. The wizard deploys and configures prerequisites and components required for the connection, including sync and signon. Azure AD Connect encompasses functionality that was previously released as Dirsync and AAD Sync. These tools are no longer being released individually, and all future improvements will be included in updates to Azure AD Connect. Azure AD Connect GA was released to the public on 24 June 2015 The GA release offers the following high level options: Dirsync Upgrade. Organizations with an existing Dirsync deployment  can upgrade in place (for directories with less than 50,000 objects) or otherwise migrate their Dirsync settings to Azure AD Connect Express Settings. Express Settings is the default option and deploys sync with the password hash sync option for a single forest. This allows sign on to cloud resources based on Active Directory passwords. Custom Settings. With custom settings, the administrator can connect one or multiple Active Directory forests and choose between password hash sync, pass-through authentication, and Active Directory Federation Services (AD FS) for signon. Custom settings also allows the administrator to choose sync options such as password  reset write back and Exchange hybrid deployment. What it does. When an administrator installs and runs the Azure AD connect wizard, it performs the following steps: