OK, so it started as DirSync, is still being called on some pages “Azure AD Connect”, including the download page as of this writing:
www.microsoft.com/en-us/download/details.aspx?id=47594
but it is, apparently, officially renamed Microsoft Entra Connect:
learn.microsoft.com/en-us/entra/identity/hybrid/connect/whatis-azure-ad-connect-v2
except within the URL itself :-)
Please note that this is NOT the same as Microsoft Entra Cloud Sync. The above does LDAP, Cloud Sync does not.