How to Stop Search Engines from Crawling your Website

search engine crawlers are very required to reach audience to your website, but if they hit continuous it will harm your website performance, If you want to prevent search engine crawler to crawl here is first and basic way to do that i.e. robot.txt

robot.txt is file which tells crawlers to what part of your website need to crawl and what part or directory not, but in written format, robot.txt follows a format to let the crawls bots to performs on your website, it also block  and allow different bots by there names