An object whose contents and attributes can be accessed through operating system interfaces. Here an ordinary file means a byte sequence with file metadata, distinct from a file-system directory or a symbolic link. Its contents need not disappear when the creating operating-system process ends.
A computer file whose logically zero-filled regions need not occupy physical file data blocks. The file offset and byte length describe the logical content independently of the blocks actually allocated.
A byte position measured from the start of a file, beginning at zero. A memory-mapped file combines a starting file offset with a displacement inside its mapping; this is distinct from an open file description's current read/write position.
Information describing a file, such as type, owner, access permissions, size, timestamps and hard link count. In the toy layout, the inode carries these attributes; the directory entries carry the names. The distinction matters because renaming a file need not copy its contents.
A storage unit holding part of a file's contents. The toy inode references two four-byte file data blocks for six bytes of contents: allocated capacity is bytes, while logical size is bytes. This counts only the two file data blocks, excluding storage for the inode and directory entries.
