Think it through together · A little story
A girl knows the library’s name but not its address. A robot helps her look it up in a directory. Domain names on the internet need a similar kind of lookup.
Lay out the process
- Enter a domain nameStart a lookup
- DNS recordsProvide related information
- Get an addressThen connect to the service
DNS is a distributed, hierarchical domain name system that stores and looks up records associated with names.
A common use is resolving a domain name to an IP address, but DNS also has other records, including records for email. It is like a directory managed by many parts, not one computer containing every piece of information.
Lookup results may be cached, so the full process does not need to be repeated next time.
Your turn to try
After DNS finds an address, has the webpage content definitely been downloaded?
Have you thought it through? Open for an explanation
No. The device still needs to connect to the website’s service, send a request, and receive the content. A directory is not the book itself.
Take away one discovery
DNS is a distributed, hierarchical domain name system that stores and looks up records associated with names.
Try covering the diagram above and explaining each step to someone in your family. If one step is hard to explain, go back and look at that card again.