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The Internet - Coggle Diagram
The Internet
What is the internet?
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Information is made of bits, a binary digit. It can only hold 2 values, 0 or 1.
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Bits are sent by electricty, light, or radio waves.
Band width is the amount of data transmitted with an internet connection in a limited time. It is meassured with bit rate.(The number of bits that we can send in a given period of time)
Information is moves long distances through light, using a fiber optic cable. A thread of glass, ingeneerd to reflect light.
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To move information wirelessly radio waves are used, but these are only short range. : : : :
Everything on the internet, videos photos or music, come down to 1s and 0s being delivered by electronic pulse, light beems, and radio waves.
Cybersecurity and crime
A computer virus is a executable program, that gets installed, usually unintentionaly, and harms a user and their ccomputer. :
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An attacker can infect a computer by luring them to install a program. Once a virus is in your computer, it can steel or delete any of your files, or even allow someone else to control your computer.
Hackers can take over millions of computers worldwide, and use them to take down websites
This attack is called a destributed denial of service.This is when hackers overwhelm a website with to many requests.
Other technique used is phishing scam. This is when you recieve what you think is a trustworthy email, that tricks you into getting your perdsonal info.
90% of times a system gets hacked, it is by a simple mistake made by a human.
Ecryption
Even though the internet is a open system, there is still exchange of private data like credit cards, bank information, passwords, etc.
Data is kept secret by a process called encryption. The scrambling or changing a message to hide a original text.
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When the sender and the reciever use the same key to scramble and unscramble a message, it is called symmetric encryption.
Computers use assymetrc encryption. A public key that can be exchanged with anybody, and a private key that is not shared.
Every time you see the letters https in your browser, it means your computer is exchanging data safely with the website.
IP adresses & DNS
The internet is a design philosphy and an architecture, expressed in a set of protocols.
A protocol is a set of rules and standards, used to communicate between machines.
All different devices around the globe have adresses. Each adress is a set of numbers that is unique in each device on the network. This adress is called the IP adress.
The Domain name system (DNS), associates names with their corresponding adresses.
Your computer uses the DNS to look up the domain names and get the assosiated IP adress, wich is used to connect your computer to the destination on the internet.
Packets and routing
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Special computers on the internet called routers act as traffic managers to keep the packets moving through the networks smoothly.
Every router keeps track of multiple paths to send packets, and chooses the cheapest path for each piece of data based on the destination IP adress.
Often, the best route for data to travell isnt the most direct.
TCP, transmission control protocol, manages the sending and recieving of all your data as packets
How search works
Search engines are constantly running a program called a spider, that cross through theses search engines to collect information about them.
for each page a spider visits, it collects any information it might need for a search, by adding it to a database called the search index.
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Search engines regularly update their search algorithms to prevent fake sites from reaching the top.
To understand words better machine learning is used. A type of artificial inteligence used to teach computers without them being explicitly programed.
Origins
Bob kahn and Vint Cerf began to work the design of what today we call the internet, in the early 70s.
[The Internet was the result of an other project called the Arpanet. It was a defence department research project.]
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He had the idea to break this messages up into blocks, and sending them as fast as possible through the mesh network
Http & Html
Http stands for hypertext transfer protocol. Its the language computers communicate ith each other. These mostly consist of get request. Get + URL of a document.
HTML stands for hyper text markup language. A system for displaying material retrieved over the Internet. Its the system to design web pages.