4. internet, you say? what is an internet?
◦ global network of connected
devices
◦ client: a computer/program used
to access information or services
on another computer/program
◦ server: a computer/program that
provides information or services
to another computer/program
5. how does one connect to this “internet”?
◦ LAN (local area network)
◦ ISP (internet service provider)
◦ IP address (internet protocol)
7. speaking the same language
◦ router: directs data to the
appropriate place
◦ TCP/IP (transmission control
protocol/internet protocol)
◦ TCP = what is it
◦ IP = where is it going
8. data transfer
◦ information that is being sent is
broken down into “packets” via
TCP
◦ routers forward the data
packets to their destination
using decentralized
transmission
◦ inbound packets are
reassembled upon receipt via
TCP
12. names and addresses
◦ did you know? people generally
cannot retain or process
information as well as computers
◦ a domain name is essentially an
alias for an IP address
◦ by using the domain name system,
domains can be mapped to a
number of internet resources and
functions
14. names and addresses
◦ URL: your request
◦ prefix: what type of resource you
are looking for
◦ subdomain/host name: subsection
of a domain
◦ domain: the server you want to
access
◦ subfolder: the location of your
request on the server
16. finding a resolution
◦ when you enter a domain name
into your browser, you issue a
request for information
◦ that request is transmitted to a
domain name server that
directs your computer to where
that information can be found
◦ packets are sent back to your IP
address from a web server
17. web/mail servers v name servers: dawn of justice
◦ name servers: contain
information related to the
location of resources associated
with a domain
◦ web servers: house site content
◦ mail servers: handle and store
messages being relayed to or
from a domain name
20. binary view
yes no
are you connected to
the internet?
HTTP request sent from
your IP address
error displayed for no
internet connection
does the domain exist?
request is routed to the
domain name server
browser error displayed for
failure to resolve domain
is there a website
associated with the
domain?
request is forwarded to the
site’s IP address/web server
user is directed to a parking
page
is there a page located
at the requested URL?
web server packets
returned and interpreted by
browser
404 error displayed for page
not found