1) Internet Flashcards
Say outloud as many things that come to mind when you see the attached image:
The image is that of Binary code, represented in zeroes and ones.
Binary code is the method in which a computer at the most base level represents data. So all that binary code coul really just be computer representations of text, numbers and images .
0 = zero, 1 = one, 10 = two, 11 = three, 100 = four, and so on.
Programming languages have come a long way in simplifying the process of writing modern software, but computer scientists interested in working with higer level computer code may be interested in increased their knowledge of binary code.
Create a dialogue around the related words:
ASCII
Unicode
Bit Unit measure
Electro magnetic things can best understand binary commands, and since this is the base of all computer communciation encoding schemes needed to be created to help translate binary code to text. US-ASCII was created to develop this initial scheme for computing.
ASCII allowed for 8 bits (1 byte) and only allowed for 256 possible characters. ASCII would be enough if only to account for english language characters, but to standardize coding for global use more characters are needed.
Unicode introduced 16 bits, a 16 bit character can have 65,536. A 32 bit character can have 4,296,967,296.
How is information saved on your computer, why is the process bad, and what is the rememdy when trying to speed up ones computer?
Information is saved constantly when we use our computers. Computers are lightning fast when they are brand new but as we start deleting files something called slackspace develops in the areas the files once sat (none of which we see). When we save new files our computer fills in the gaps which were once filled with files, this is problematic since single files can end up being located all over the place, causing fragmentation, and this is why our computers slow down over time. When we defragent our computers we pull files together.
If the smallest measure of information is a bit, what is 8 bits?
100 bits?
1000 bits?
1,000,000 bits?
1 billion bits?
1 trillion bits?
1 bit = 1 bit
8 bits = 1 byte
1000 bits = 1000 Kilobits
1,000,000 bits = Megabyte
1 billion bits = Gigabyte (think billionaire Elon musks gigafactory)
1 trillion bits = Terabytes
What happens when you boot up your PC?
When you boot up a (microsoft) PC you’ll see firmware running, the job of firmware is to run upon system load checking to see if everything is in order using a POST (power up self test, during which the firmware checks if anything is broken, and checks the RAM) which runs a BIOS (Basic input output system) before passing control over to the OS.
What is the CPU, RAM, and the Hard Drive?
The CPU is the brain of the computer and it runs on GHz. RAM (random access memory) is cache memory, volatile, but quick to access, and I believe it is typically only 2gb. Ones Hard drive can be thought of as (permanent) long term memory, it is larger than RAM, but slower to get things from.
This raspberry Pi is a miniature computer, list out all the components you know.
Imagine a CPU, what components does it have.
If I typed in google.com into my browser address bar and click enter, what happens?
Assuming everything is in working order and your computer is connected to the internet and speed is normal and google isn’t a blocked website in your country, you would send your address in the form of a web request by way of your ISP provider to a DNS (domain name server) address book type server. The DNS translates your domain name into an IP address, and the DNS system then goes through several servers to find the location of your required google location. Once google is found the google servers send your computer an html file in packets (and continues to send those files if the server notices any packets failed to make the journey to your computer) and your browser reads the html file and displays it beautifully on the screen.
Describe an HTML page, what is on it?
Also give detailed explanation of htmls purpose in Progressive Enhancement.
HTML is made up of a head and a body, but starts of with a link hreffed to styling before the head, and ends (just below the body) with scripts sourced. A doctype declaration is necessary to start of the page and a meta charset declaration is optional (at least in html5).
HTML is hypertext markup language. It is the content layer of PE. It can be text, or images or stylized boxes but it (content) is king. Programmers can write their styling inside html (but that’s not advised).
What is CSS?
CSS means cascading style sheets and it is the presentation layer of the progressive enhancement pardigm. It has 3 key features that well summarize its use: the fact that styling cascades, specificity and inheritance (children take on the styling of their parent elements unless otherwise styled).
What is JavaScript?
JavaScript is the behavioral layer of the Progressive Enhancement paradigm.
What is an IP address and what do you know about it? Describe why information might take longer to be delivered to users computers, and how companies like Google seeks to reduce this lag.
An IP address is the location or address of any file on the world wide web. IP (internet protocol) addresses are broken up into 4 parts, each one being able to hold a number from 0 to 256, and each of those parts being called octets. IP addresses can be private, and when they are they have special first numbers.
Depending on the proximity of the servers your file may be slowed down or sped up by latency (wait time). Companies like Google reduce latency by creating a large number of servers close to users (including recently flying hot air ballons in some developing countries) and even creating multiple servers that do the same thing, creating redundancy, so that if one server crashes there is load balancing that occurs.
What is TCP? What is IP?
TCP and IP work together as two layers to get data to help you interact with the outside world wide web. IP is internet protocol and it is the main way you get data by addresses. TCP (transmission control protocol) is the way in which you send out or communicate content to the WWW. With TCP you establish and maintain network communication between your computer and a server or someone elses server, or an intranet or extranet. TCP is the top layer that creates packets out of data you want to send and when it receives packets it puts the packets together to make one whole file for the user to see. IP is focused on addresses and will send out individual packets of information to their appropriate destinations.
TCP/IP uses the client/server model and point to point, what do those terms mean? Everytime a single request is made something interesting happens, what is that thing, and what is the term for it called?
Client/server model represents the way in which users request information from a server and receives service from that server. TCP/IP communication is point to point, or host computer to host computer in the network. Everything the TCP/IP system makes a request on behalf of the user as soon as it receives a response from the appropriate server that request is dead, and no more, this concept is called stateless. Every request stands on its own.
How do servers listen in to what users are doing when everytime our computer talks to a server our computer seems to drop the phone or cut the line and end comunication with servers everytime a response to a request is received.
Out TCP/IP system routinely cuts off communication with servers after they get what they want, so for users to be able to save their progress as they move around websites we can’t save their sessions on the servers, instead we use cookies. Cookies act as cached memory to save information about a users session that may be important to that user.
Before being able to even send requests to the ISP (which then talks to a DNS system) for a website what were old web travelers required to do? What modern solution makes this tedious thing easier today?
Web users had to collect information and type them into their computers. Today a DHCP (dynamic Host Configuration Protocol) system is the first step in the web request making process because it automatically syncs up your IP address, router, subnet mask, and list of DNS servers.
How does geolocation work?
Geolocation works because IP addresses are distinct in distinct places. When your computer is linked to the internet any where around the world it is often linked to a identifying IP address that is unique to the location or servers in your area.
What is a VPN?
VPN is virtual private networking, and it is great. It’s one way to surf the web while encrypting your data as you surf the web, you use a secure network connection often over private or public wifi to help keep your work private and secure. VPNs provide secure network connections at a COST, sometimes in monies and in speed, but should always give you anonymity from snoopers.
If you wanted to learn more about the travels of your ISP what would you do?
You could utilize your CLI (command line interface), on teh Mac its called the Terminal, and at your prompt you’d enter a traceroute command. So inside your cli you could type in: $ traceroute google.com. You could also get information about the host by typing in $ host google.com.
What is a domain, a sub domain, and a TLD?
A TLD is a top level domain and it’s represented by the letters after the final dot in a domain name, the domain name is everything just before the TLD, and the subdomain is the name just before the domain name.
