Which command is used to change a directory in Linux?

The command used to change a directory in Linux is "cd," which stands for "change directory." This command allows users to navigate through the filesystem by changing the current working directory to the specified path. For example, executing "cd /home/user/Documents" would change the current directory to the Documents folder located in the user's home directory.

In contrast, the other commands listed serve different purposes. "mv" is used for moving or renaming files and directories, "ls" lists the contents of a directory, and "chmod" changes the file permissions but does not affect the directory itself. Thus, "cd" is specifically designed for directory navigation, making it the correct choice for this question.