What is Internet?
what is internet?
INTER connected NETWORK
made up to an incredibly large number independently operated network and fully distributed
it was a result of another experiment called ARPANET (Advanced Research Project Agencies Network)
to access information, send/post message, communicate with friends and family
how search work
search engine running program 'spider' that collect the information
the internet is a web of page connected to each other by hyperlink
search engine are constantly scanning the web in advance
search index is a database or information used for doing a research
search engine's ranking algorithm check from the title, sequence or keywords
cyber-security & crime
cybercrime causes huge problems for society personally,financially and even in matters of national security
encrypting & public keys
public keys
encrypting
data of any kind can be kept secret through a process
scrambling or changing of the message to hide the original text
method of encryption was Caesar's Cipher
can be exchanged with anybody
used to encrypt data & anybody can use
can be exchanged with anybody
used to encrypt data & anybody can use
wire,cable &wifi
passage by electricity, light & radio waves
bandwidth
measured by bit rate
latency
different measure of speed
send bits as light beams from one place to another using a fiber optic cable which is the alternative when it in the long distance
wireless bit sending machines typically use a radio signal to send bit from one place to another
IP addresses & DNS
DNS (Domain Name System)
IP addresses is computer's address
is when computer asking anotehr computer for information
is bunch of number and organized hierarchy and each represent bit
associate name like www.sophia.com with corresponding addresses
is used to connect computer to the destination on the internet
DNS server are connected in a distributed hierarchy & divided into zone, splitting major domain (eg: org,com, net)
packets, routing & reliability
routers/moderms
reliability
packet
TCP (Transmission Control Protocol) manage the sending & receiving all your data as packets
information on the internet goes from one computer to another in a packet of information
each router keep track of multiple path for sending packets & choose the available path
traffic manager to keep packet moving through the network smoothly
key principle of internet
the more router/moderms the more reliable the internet