The main services for protocols are to transfer the data in a flexible way. The OPC UA services are defined in more precise way.
A lot of different types of communication protocol is needed for communication between the devices but is it different from OPC UA.
Without any communication protocol, Industry 4.0 is also just a term. So, the usage of OPC UA platform in Industry 4.0 has been explained.
In industrial communication sector, a standard line of data exchange is required between machine to machine or PC to machine.