Spider is used to crawl a website to quicker index in search engine.

Spider is a program to run by a search engine to build a database of website content.

Spider, Crawler & Bot all are having the same meaning. It is nothing but the program which indexed your webpage which includes Text or Image(if ALT tag mentioned).

Crawling is the process by which the google bot discovers new and updated pages to be added to the google index we use a huge set of computers to fetch billions of pages on the web the program that does the fetching is called googlebot (robot, bot, spider)

Spiders differ from other arachnids in having the body divided into cephalothorax and abdomen. About 43,000 spiders are known, but many have yet to be discovered and described.

A spider is a program run by a search engine to build a summary of a website’s content (content index). Spiders create a text-based summary of content and an address (URL) for each web page.

spider is a search engine program that is responsible to find and read through webpage

Spider is a robot of every search engine which crawl your website.

The spider is an software program travel the web locating and indexing websites for search engines all the search engine use the spider for build and update their index.

it is crawler which crawls the website

Spider is software,to crawl website and store the information in their database....

A spider is a program that visits Web sites and reads their pages and other information in order to create entries for a search engine index. The major search engines on the Web all have such a program, which is also known as a "crawler" or a "bot."

Spider is called as crawler is to indexing a webpage.

A spider is a program that visits Web sites and reads their pages and other information in order to create entries for a search engine index. The major search engines on the Web all have such a program, which is also known as a "crawler" or a "bot." Spiders are typically programmed to visit sites that have been submitted by their owners as new or updated. Entire sites or specific pages can be selectively visited and indexed. Spiders are called spiders because they usually visit many sites in parallel at the same time, their "legs" spanning a large area of the "web." Spiders can crawl through a site's pages in several ways. One way is to follow all the hypertext links in each page until all the pages have been read.

Google uses spider to crawl the webpages.
Spider is software program used to automatically discover the pages in the web in order to index them in the database.