This sounds like something to do with computer programming; perhaps dynamic web design?
You have a "node" (that's a technical term for something). This node has an "attribute" associated with it. This attribute acts like a variable: it contains a piece of information. This piece of information may just be a simple value, or it may be something that says, "This node is connected to node X."
What is an attribute?
Well, think of a car. This car has many different attributes: colour, engine size, maximum speed, number of gears, fuel consumption and so on.
The attribute "colour" (for example) contains a value which tells you something about the car. It may be "blue" or "red" or "silver", for example.