What is the purpose of a robots.txt file?

The purpose of a robots.txt file is to instruct search engine bots on how to crawl and index the pages of a website. By specifying rules in this file, website owners can communicate which parts of their site they want search engines to access and which parts they prefer to keep out of the crawling process. This is important for controlling the visibility and indexing of specific areas, such as private pages or duplicate content, ensuring that search engines focus on the most relevant content.

This capability allows webmasters to guide the indexing and crawling behavior of search engines, which can result in better handling of website traffic and potential search visibility. The other options refer to functions not performed by robots.txt files, such as managing content visibility directly to search engines or specifying user agent information, which are outside the typical scope of what a robots.txt file accomplishes.