| Application | A Grafchart program. |
| Command Line Argument | Parameters passed to a program when it's started to customize its behavior. |
| Compile | Check an application for errors and prepare it for execution. |
| Custom IO | An implementation of the digital and analog inputs and outputs. Which implementation to use is specified by a command line argument to JGrafchart. |
| Grafchart | The programming language that all applications in JGrafchart are written in. |
| Local IO | Same as Custom IO. |
| Scan | Same as Scan cycle. |
| Scan Cycle | The application is executed periodically with an application specific period time. One such execution period is called a scan cycle. The period time has many names, e.g. scan cycle interval, scan cycle period, and scan cycle time. |
| Startup Script | The files used to start JGrafchart. They are located in bin/. |
| Top-level Workspace | The topmost workspace of an application. Each application has exactly one top-level workspace. |
| Workspace | The working area for a part of an application. |