Pure Data has two modes — Edit Mode for building patches and Run Mode for playing them

Pd separates building from performing through two modes of operation. Edit Mode (toggled with Ctrl+E / Cmd+E) is for creating, moving, and connecting objects; clicking an object in this mode selects/edits it rather than triggering it. Run Mode (called that only by convention — the software gives it no name, it is simply ‘not Edit Mode’) is for interacting with the patch as an instrument: clicking triggers, dragging changes values. The title bar and the mouse-cursor icon both change to signal which mode is active. Because patching means switching between the two constantly, learning the Ctrl+E shortcut by heart is worthwhile; holding Ctrl also drops you into Run Mode momentarily while held.

Examples

Pressing Ctrl+E to enter Edit Mode, placing an osc~ object, then leaving Edit Mode to click and test it; the mouse icon and title bar change as you switch.

Assessment

What happens when you click an object in Edit Mode versus Run Mode? Why is the Edit/Run distinction useful in a realtime audio environment?