Protection effect
The feature applies WordPress’s file-editor restriction at runtime. Logged-in users can no longer edit plugin or theme code directly through the built-in backend editor.
Why does this matter?
If an administrator account is compromised, a disabled file editor removes one direct route for inserting malicious code.
No file modification
WM Guard does not write a constant into wp-config.php. The effect exists only while the protection is enabled and the plugin is loaded.