Dictionary.net

A data flow architecture or language performs acomputation when all the operands are available. Data flow isone kind of data driven architecture, the other is demanddriven. It is a technique for specifying fine-grainconcurrency, usually in the form of two-dimensional graphs inwhich instructions that are available for concurrent execution arewritten alongside each other while those that must be executed insequence are written one under the other. Data dependenciesbetween instructions are indicated by directed arcs. Instructionsdo not reference memory since the data dependence arcs allow datato be transmitted directly from the producing instruction to theconsuming one.Data flow schemes differ chiefly in the way that they handlere-entrant code. Static schemes disallow it, dynamicschemes use either "code copying" or "tagging" at every pointof reentry.An example of a data flow architecture is MIT's VALmachine.