A Data Flow symbol is a line indicating the direction of the flow of data as it moves from one point in the system to another.

Data flows can split into two or more flows, or they can join to one from two or more flows. Orthogonal lines are traditionally used in Gane & Sarson DFDs; elliptical arc lines are traditionally used in Yourdon/DeMarco DFDs.

Data Flows are defined with the names of data elements and data structures, which can consist of any characters. If the letter contains characters other than letters, enclose the entire name in double quotation marks: