Web copywriting
Copywriting specifically aimed at an online audience. It shares many of the ground rules of offline copywriting, but has quickly evolved to become a stand-alone science. Recently it has also begun taking into account how spiders see web pages. Although there are many who feel copywriters should focus on converting visitors to customers and not be concerned with getting visitors, there are strong arguments for SEO considerations to form part of web copywriting.

Web Crawler
web crawler (also known as web spider) is a program which browses the World Wide Web in a methodical, automated manner. A web crawler is one type of bot. Web crawlers not only keep a copy of all the visited pages for later processing - for example by a search engine but also index these pages to make the search narrower.