Lesson.

I'm going to share something that I just learned with you:

"A 'spider' is also a computer program that searches the World Wide Web automatically by retrieving a document and all linked documents for storage in a database. These programs are also called either 'web spider' or 'web crawler' or 'web robot'. The search process is called 'web crawling' or 'spidering'."

- Anonymous 

Web of Knowledge, 2011