1. what is the difference between read and synchronous read in file adapter?Read is use for polling. Read option will initiate a new instance(and you will use a receive activity - inbound).
2. how synchronous read operation is outbound operation? Read must be an Inbound operation.Synchronous read is being used from an existing instance (process). You will use an invoke activity for that - you are sending a request to read a file (file/directory name etc..). You are then getting back the result (file content etc....).