MS-DOS command types: In DOS, which category describes commands that are stored as individual program files on disk (for example, on the hard drive or a DOS diskette), and are loaded by the command interpreter only when invoked?

Introduction / Context:
Classic MS-DOS provides two broad categories of commands: internal commands that reside within COMMAND.COM, and external commands that are stored as separate executable files (such as .COM or .EXE) on disk. This question checks your ability to distinguish how DOS provides functionality and how the command interpreter locates it.

Given Data / Assumptions:

• DOS uses COMMAND.COM as the default command interpreter.
• Some commands are available immediately after boot (internal), while others are loaded from disk when used (external).
• Examples help clarify the classification.

Concept / Approach:
Internal commands (for example, DIR, COPY, DEL in many DOS versions) are built into COMMAND.COM and need no separate disk files. External commands are separate programs (for example, FORMAT.EXE, CHKDSK.EXE, XCOPY.EXE) that DOS loads into memory on demand. If the file is not on the current drive/path, the command will not run.

Step-by-Step Solution:

Verification / Alternative check:
Type HELP or look for a command’s corresponding .EXE/.COM on disk. If present and removable from PATH, the command is external; if removing it breaks the command, it confirms the classification.

Why Other Options Are Wrong:
Internal: embedded in COMMAND.COM, not separate files. Change/File: not standard DOS command categories. None of the above: incorrect because “External” is the accepted term.

Common Pitfalls:
Assuming every frequently used command is internal; confusing availability with classification; forgetting that different DOS versions may classify a few commands differently.

Final Answer:
External