What is data aggregation?
Data aggregation is the bringing together of data from different OPC servers (and other data sources) into a single data source, so that one or more OPC clients (or other clients) can access this data through a single common interface.
Depending on what solution you choose, data aggregation is about more than just OPC - it's about centralized collection of data from all of your various data source to create a comprehensive data set for your entire enterprise.