For the control of 400/132 kv substations , Kindly i need answers for the following questions please:

1- Whats the difference between MicroScada and SCS?
2- What is the speed of the communication inside the Scada system, i e between the servers and IED's?
3- Whats is the difference between protocols IEC 60870-101 and IEC 60870-104?
4- Why most of control centers are using 101 for the data received?
5- Do we need to replace the hard disk for Scada servers due to that it will be full storage capacity after specific time or the data is replaceable and stored in a way that the old data is erased after fully storage capacity?
Thanks a lot dear brothers