The Go|Next File menu item activates the next file tab in the current project. If the last file in the project is active, then the first file is activated.
If you record this command as part of a macro and the macro plays back the Go|Next File command when the last file is already active, then macro playback is stopped. The first file is not activated. This makes it possible to record a macro that operates on all files by recording Go|Next File as the last command in the macro. Then you can play back the macro and repeat it any number of times, knowing that it will stop at the last file.
The Next File and Previous File commands always switch between files in the order their tabs have. If you want to switch between recently edited files, use the Go|Back in Edited Files and Go|Forward in Edited Files commands. If you want to switch between recently viewed files, regardless of whether you've edited them, use the Ctrl+Tab key combination with the "use most recent order when switching tabs with Ctrl+Tab" preference turned on. If you quickly want to go to a specific file, use the Files Panel.
Go|Back in Edited Files
Go|Forward in Edited Files