What is Index of and how do I disable the automatic display of a directory's contents?

If a link points to a directory that does not have an index file set (e.g., index.html, default.html, etc.), then the content of that directory will be displayed. Example of display:

To disable the automatic display of directory content, we will create the .htaccess file in the respective directory, a file in which we will add the following line: Options -Indexes

Note: This solution is only valid for the Apache web server. Other web servers operate with different directives and configuration files.