An Information Flow represents information items or classifiers flowing between two elements in any diagram. The connector is available from the Common page of the Toolbox and from every Quick Link menu.
You can have more than one Information Flow connector between the same two elements, identifying which items flow between the two under differing conditions.
OMG UML Specification
The OMG UML specification (UML Superstructure Specification, v2.1.1, p. 606) states:
An InformationFlow specifies that one or more information items circulates from its sources to its targets.
The OMG UML specification (UML Superstructure Specification, v2.1.1, p. 607) also states:
An information flow is an abstraction of the communication of an information item from its sources to its targets. It is used to abstract the communication of information between entities of a system. Sources or targets of an information flow designate sets of objects that can send or receive the conveyed information item.