Final answer:
Children items appear by default in the order they were added, whether it's in a programming environment, an HTML document, or a file system; the exact order can depend on platform and settings.
Step-by-step explanation:
The question 'In what order do children item appear by default?' seems to be related to a concept in computers and technology, particularly concerning user interfaces or programming where different items, such as files, menu options, or UI elements, could be considered as children within a parent container or list.
By default, children items typically appear in the order that they were added to the parent container. For example, in most programming environments, when you add elements to a layout or a data structure like an array or a list, the items show up in the sequence they were added, unless explicitly sorted or arranged otherwise.
However, the exact default behavior might differ based on the platform, environment, or the specific language you are using. In web development using HTML, children elements in a <ul> or <ol> will appear in the order they are written in the HTML document. In file systems, children items such as files within a directory may appear ordered alphabetically by default, but this can vary by file system and user settings.