A robots.txt file tells search engine crawlers which URLs the crawler can access on your site. This is used mainly to avoid overloading your site with requests; it is not a mechanism for keeping a web page out of Google.

Commands can be set up to apply to specific robots according to their user-agent (such as 'Googlebot'), and the most common directive used within a robots. txt is a 'disallow', which tells the robot not to access a URL path. You can view a sites robots. txt in a browser, by simply adding /robots.

The Robots Exclusion Standard was quickly embraced by the web community. Most major search engine crawlers adopted it, respecting the rules outlined in robots. txt files. While it's a voluntary protocol (bad bots can ignore it), the vast majority of web crawlers still abide by it.