These are officially called Menu Bar Extras (or "Status Items"). They sit on the right side of the top Menu Bar, next to the clock and Siri icon.
You can also drag tray icons directly to reorder them or move them in/out of the overflow menu by dragging to/from the chevron ^ . what is a tray icon
Usually opens a "context menu" for quick actions like "Quit," "Settings," or "Pause". These are officially called Menu Bar Extras (or
NOTIFYICONDATA nid = sizeof(nid) ; nid.hWnd = hwnd; nid.uID = 100; nid.uFlags = NIF_ICON | NIF_TIP | NIF_MESSAGE; nid.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_MYICON)); lstrcpy(nid.szTip, L"My Background App"); Shell_NotifyIcon(NIM_ADD, &nid); nid.hWnd = hwnd