🎮 Medium Example: Roblox Game Login System

Top module: \"Play Video\" \u2014 this is the main module that controls everything
Lines going down: \"Play Video\" calls (uses) three sub-modules
Bottom modules: Each handles one specific job:\n \n \"Load Video Data\" \u2014 fetches the video file from YouTube's servers \n \"Display Player\" \u2014 shows the video player on screen with controls \n \"Track Watch Progress\" \u2014 remembers where you are in the video \n

Let us look at a more detailed structure chart. This one has three levels and shows data flow:

🔍 Trace the Data Flow

"Get User Input" collects the username and password and passes them up ▲ to the main module
"Login System" passes them down ▼ to "Validate Credentials"
"Validate Credentials" sends the username down ▼ to "Lookup Account" which returns the stored password up ▲
"Compare Passwords" receives the typed password and stored password down ▼, returns whether they match up ▲
"Validate Credentials" combines the results and returns is_valid up ▲
"Display Result" receives is_valid down ▼ and shows success or error

🎯 Exam Tip

In an exam, you might be asked to "trace the data flow" through a structure chart. Follow the arrows and describe what data moves where, just like we did above. Always mention the direction (passed down / returned up) and the data name.