Which command is used to create a new directory in the CLI?`add``create``newdir``mkdir`

Step 1: Break Down the Problem

We need to identify the correct command among the given options that is used to create a new directory in the Command Line Interface (CLI).

Step 2: Relevant Concepts

To create a new directory in CLI environments (such as Unix, Linux, or Windows), there are specific commands associated with this action.

Step 3: Analysis and Detail

1. add: Not commonly used for creating directories.
2. create: This is a general term but is not a standard command for directory creation in CLI.
3. newdir: This is not a command recognized in standard command line environments for creating directories.
4. mkdir: This is a well-known command across various operating systems (like Unix/Linux and Windows) that stands for "make directory".

Step 4: Verify and Summarize

Among the options provided, mkdir is the valid command used to create a new directory in the CLI. The other options do not correspond to this function.

Final Answer

The correct command to create a new directory in the CLI is mkdir.