Operating Systems and File Management
Role of an operating system
An operating system is a resource manager and an interface between the user and hardware. It handles process scheduling, memory allocation, device management and file management. A GUI uses icons/windows; a CLI accepts typed commands. Booting loads the OS kernel into RAM, often via firmware.
File-management rules
- A file has a name, extension, location, size, timestamps and attributes such as read-only, hidden, system and archive.
- A directory tree organises files. An absolute path starts at the root or drive; a relative path starts from the current directory.
- Operations include create, open, read, write, append, rename, copy, move and delete. Closing a file releases buffers and updates metadata.
- Extensions indicate expected format, not guaranteed content: renaming .txt to .jpg does not convert the data.
Worked example
For C:\School\CS\notes.txt, the drive is C:, the directories are School and CS, the file name is notes and the extension is .txt. The path is absolute because it begins at the drive root. From C:\School, the relative path is CS\notes.txt; from C:\School\CS, it is simply notes.txt.
Traps
Do not treat a shortcut as the original file. Do not say deleting a folder always removes every file without confirmation/recycle behaviour. The extension is not proof of file type. A relative path does not include the drive unless explicitly written.