A robots.txt file is a file used by web servers to communicate with web robots (also known as “bots” or “crawlers”) about which pages or sections of a website should or should not be crawled and indexed. The default content of a robots.txt file can vary depending on the web server and the specific configuration, but a basic example of a robots.txt file might look like this:
User-agent: *
Disallow: /
This example tells all web robots to disallow access to all pages of the website (the / symbol is a wildcard that matches all pages).
In general, you can create a robots.txt file with any text editor and place it in the root directory of your website. You can then use the User-agent and Disallow directives to specify which sections of your website should or should not be crawled by web robots.
It’s important to note that while the robots.txt file is a widely recognized standard, it is not universally respected by all web robots. Some web robots may ignore the robots.txt file and crawl your website regardless, so it’s not a foolproof method of controlling access to your website. For more secure control over access to your website, you may need to implement additional measures such as server-side authentication or IP blocking. (Xanax)