QEMC= QlikView Enterprice Management Console QMC= QlikView Management Console If I'm not misstaken the QEMC comes with Publisher and QMC with Server. As of QV 11 there will only be a QEMC. If you have both use what ever suits you.
1>One of the major difference between QMC & QEMC is that you can manage multiple instances of qlikview server using QEMC but not by using QMC & also there are sevral settings & configuration which is not possible from QMC like Active Directory setting,command center configuration,
changing the database for creating QVPR(like from xml to sqlserver) etc
2>QEMC is used when you are dealing with cluster of server and QMC when you are dealing with one instance of server.
3>QEMC have Publisher by which you can also apply section access
QEMC is more functional than QMC, as others have stated, and would be the tool of choice if you are clustered and/or using Publisher. However, even if you only have a server license and a single instance, you can use whichever tool you wish - it just depends on which you are more comfortable with.