Types of Commands
Commands are classified into two types:
1. Internal Commands: These commands are part of the operating system and reside within COMMAND.COM or cmd.exe. When you execute an internal command, MS-DOS executes it immediately. They’re always available as part of the shell and don’t require independent files.
2. External Commands: These commands are for advanced tasks and require external file support as they’re not stored in COMMAND.COM. They’re stored separately and can be added to Windows as required.
Additionally, there are Batch files containing lists of internal and/or external commands executed sequentially when the batch file runs. AUTOEXEC.BAT automatically executes on booting.
What is an Internal Command?
DOS Commands are important instructions for managing files and directories in Windows. They’re case-insensitive and follow the 8-dot format for file names. Each file has a primary name (up to 8 characters) and a secondary name (up to 4 characters with a dot). Common secondary names include .txt for text files, .com for command files, .sys for system files, and so on.
Special characters like < > , . / * ? | & Space are not allowed in file or directory names.
Internal commands are integral to Windows, embedded in the command.com file, and easily accessible. They’re important for smooth operation and are always available, whereas external commands are effective tools that can fix issues, enhance performance, and perform different actions. They’re stored individually from internal commands to reduce system load. You can add external commands to Windows by copying their files to your computer when needed.