When you are on Google and you decide to do a search, you are not searching the web pages. What you are doing is actually searching Google’s index of the web page. This is done with programs called spiders. They start off by fetching a few web pages, then follow links to those pages and collect all the pages they point to; and follow all the links, and then again fetch the pages they link to, and so forth. This is done until we have indexed a huge chunk of the web.
the answer is "When searching the web software programs called spiders fetch a few web pages and then they follow the links on those pages and fetch the pages they point to, and so forth?
Fault Tolerance basically refers to the feature or capability of a system to keeps on working and performing its operations without interruption in case of a failure.
This failure can be the failure of one or more of its components.
This is beneficial as the system does not stop working or fail completely.
It provides copies of the same system or backup components which can be used when the existing system fails and prevents the loss of information and services.
Accessibility refers to provide equal services for everyone who uses a system. So its not a correct option.
Moore’s law states that the computing speed and power will double every two years so its not a correct option as well.
Anti virus is a software to identify, prevent and remove viruses and malware so it is not a correct option as well.