Difference between widget and operator - Fiware?

I just started today with FIWARE and I havent understood yet the difference between widget and operator using this platform.

While I understood what a widget using wirecloud, I still dont have clear what an operator is in this context.

Google didnt help me a lot.

Solution

A WireCloud operator is a component similar to Widgets, they are programmed using web technologies (e.g. JavaScript), but don't provide an user interface. In that sense, they are not meant to be used in the dashboard editor, but in the Wiring Editor.

Operators can be classified using three types:

Data source operators: Operators that provide information that can be consumed by other widgets/operators. For example, an operator that retrieves some type of information from a web service.
Data target operators: Operators that are provided information and use it to do some tasks. For example, an operator that receives some information and push it to a web service.
Data transformation operators: This type of operators can be very useful since they can transform data in order to make it usable by widgets or operators that expect data structure to be slightly different.

For example, in WireCloud there is a generic Map Viewer widget that can be wired through an operator to any source of information of your choice (e.g. you can use the NGSI Source operator for getting info from an Orion Context Broker). If you have a FIWARE Lab account you can get some examples by installing the OrionStarterKit or the CKANStarterKit.