Parameters
To create dependencies between object parameters, you can use the Wire Parameters feature.
Particle Flow
Particle Flow uses wires to show connections between events in Particle View. There are two types of wires: one that connects a global event to a birth event, represented by a dashed blue line; and one that connects a test to a local event, represented by a solid blue line.
Wire from global event to birth event (above); wire from test to local event (below)
To wire a test to an event, drag from its test output, the blue dot that by default sticks out to the left of the test, to the event's event input, which sticks out from the top, or vice-versa. Similarly, you can wire a global event to a birth event by dragging between the source output on the bottom of the global event and the event input.
When the wire is ready to be connected to an input or output socket, the cursor shows a small plus-sign.
To delete a wire, right-click it and choose Delete Wire, or click it (it highlights in yellow) and then press the 
key. Or, with a wire between a test and an event, drag from either connector to a blank area of the event display.
Slate Material Editor
To create a tree of materials, maps, or shaders, the Slate Material Editor uses wires between material, map, and shader nodes. See Wiring Nodes.