In terms of internet, spider refers to BOT
or the web crawler which is basically an automated computer program that takes
in an order and executes it just like a Robot. The spider crawls over the
different web pages and captures the content that is there on the page. It
stores a copy of the page and helps the search engine by providing the
information. When a user searches for something through the search engine then
the search engine processes the data that has been stored by the spider and
index it which helps it to provide the user with the required data at a faster
speed. Thus the spider or the web crawler essentially helps a search engine to
come up with the relevant data.
Some of the people also use the spiders to
get crawl over different web pages and get them specific information. For
instance, the web spider can be used for getting email addresses that can then
be used for email marketing and is also used for spamming. The web crawlers
also look out for new changes in the already crawled websites and monitors then
to note for the changes and provide with the most relevant search results. Getting
your website spidered is therefore important to show up in the SERP.