High Availability (principle+mirror+WITNESS):- High-availability mode, runs synchronously. Requires a witness Server instance. The Principal server sends the log BUFFER to the mirror server, and then waits for a RESPONSE from the mirror server.
Principle is not available the witness and mirror will decide automatic failover .mirror becomes online.

High Protection (principle+mirror):- High-protection mode, runs synchronously. Always commit CHANGES at both the Principal and Mirror. Automatic failover is not possible.

High Performance: - High-performance mode, runs asynchronously and the transaction safety set to off. The Principal server does not wait for a response from the mirror server after sending the log buffer. The principal server running nice and fast, but COULD lose data on the mirror server.

High Availability (principle+mirror+witness):- High-availability mode, runs synchronously. Requires a witness Server instance. The Principal server sends the log buffer to the mirror server, and then waits for a response from the mirror server.
Principle is not available the witness and mirror will decide automatic failover .mirror becomes online.

High Protection (principle+mirror):- High-protection mode, runs synchronously. Always commit changes at both the Principal and Mirror. Automatic failover is not possible.

High Performance: - High-performance mode, runs asynchronously and the transaction safety set to off. The Principal server does not wait for a response from the mirror server after sending the log buffer. The principal server running nice and fast, but could lose data on the mirror server.