How to search for a command?

To search for a command, you can use the apropos command or the man -k command. Here’s how to do it:

Using apropos:
```
apropos <keyword>
```
Replace <keyword> with the term related to the command you are searching for. This will list all manual pages that have the keyword in their name or description.
Using man -k:
```
man -k <keyword>
```
This command is equivalent to apropos and will provide the same results.

For example, to search for commands related to "directory":

apropos directory

This will display a list of commands and their descriptions related to directories.