What is difference between spider, crawler and robots? Or Spider, crawler and robots is same search software to craw and index webpage for the search engine.

They are all the same.. used interchangebly.

Yes, basically they all are same & used to crawl & index webpages for different search engines.

They are just different names for the same thing. "Spiders" are "Crawlers" and "Robots" is a word commonly used when talking of robot text which is where you put exclusions for the spiders not to find.

Spider, crawler  and robots both are same program to reads the text information from World Wide Web and find hyperlinks if any, then followed those links and collect all data and records it into search engine database for use of visitors.

Spider is a application program used to scan the web pages from website.

Crawler is used to crawl or index the pages from website.

Robot is a text file used for access permission to spider and crawler.

Crawler or Spider, a robot is a search engine program that crawls the web, collecting data, following links, making copies of new and updated sites, and storing URLs in the search engine's Index. This allows search engines to provide faster and more up-to-date listings.

spiders, crawler and robots are just different names for the same thing.these are different words to define the automated programs which are written to do crowling through the web. The crawlers are automated so they are called Robots and they are crawling the web (internet) so they are called Spiders.
Robots do the predefined tasks which are to download we pages and follow the links on those pages.

I too think they all are almost the same.

They are same.

Thanks for sharing the difference between Spider,Crawler & Robot.This is really beneficial information for me.

According to me spider, crawler and robots is same search software.  All works for search engine like traveling the web and find out the new update or information and links and submit it in search engine data base.

Spider - a browser like program that downloads web pages.

Crawler – a program that automatically follows all of the links on each web page.

Robots - An automated computer program that visit websites & perform predefined task.

Spider, crawler and robots all are same program to reads the text information from World Wide Web.

A program that automatically fetches Web pages. Spiders are used to feed pages to search engines. It's called a spider because it crawls over the Web.

A Web crawler is a computer program that browses the World Wide Web in a methodical, automated manner or in an orderly fashion.

A robot is a mechanical or virtual intelligent agent that can perform tasks automatically or with guidance, typically by remote control.

Hello,

Spider Scan and judge you website content ,Crawler crawl you content and index it in there searches according to Inbound links both techniques helps google to judge importance of website in terms of ranking ,robot.txt file is that file which is included into web coding so that google not consider it in crawling or to hide page from google crawling .