Question 1

How is binary conveyed in electric currents in copper wire?

Accepted Answer

Typically, one uses a modem (https://en.wikipedia.org/wiki/Modem) to convert the digital signal into an analog signal  (via modulation https://en.wikipedia.org/wiki/Modulation) i.e. it gets converted into an electrical wave. The more popular techniques used by the modems are amplitude, frequency and phase modulation.

Question 2

Can you recommend resources that dive deeper into cybersecurity?

Accepted Answer

Brit Cruise developed content here on Khan Academy about cryptography and information theory:

https://www.khanacademy.org/computing/computer-science/cryptography
https://www.khanacademy.org/computing/computer-science/informationtheory

Question 3

What is IP address?

Accepted Answer

An IP address is like a mailing address, but on the Internet.

All the data going around the Internet needs to know where it's going.  There's a huge network of cables and routers going all over the world to connect everything, but how do these routers know where to send the data?  Every packet of data has a destination IP address marked on its front.  Routers look at each packet, and decide which direction it needs to go.

Let's suppose that I, from California USA, send a packet of data to Hong Kong.  (This packet might contain a request to view a website, or part of an email, or something else; it's irrelevant what the packet contains, since the IP address is stamped on the front.)  The first router I hit knows to send it to San Francisco, because it knows from the IP address that the San Francisco link is the most direct path to Hong Kong.  Then, it gets sent across a transpacific cable.  The router at the far end of that cable sends it to the ISP of the website I'm trying to access.  Finally, it gets sent to the website's server.

The IP address is a way to identify a particular computer on the Internet, so that data can be sent to it.  Routers have tables that know which cable to send data along, based on the IP address.

Question 4

In the "HTTP and HTML" video, it is mentioned that HTML is no longer used to work with fonts and positions of words in web pages. Instead, CSS is used. Why is that so?

Accepted Answer

Because CSS is a better, more powerful, readable and organized way to do it.

Question 5

is chrome a secure website to use

Accepted Answer

Chrome is a web browser, not a web site.

Is it safe ?
As far as security vulnerabilities go, it is similar in safety to other major web browsers. It is used by a lot of people, so one would expect any vulnerabilities to be exposed quickly, and its maker, Google, seems to patch vulnerabilities relatively quickly.

As far as privacy goes, they do track user's activity, (some of this tracking is optional, some is not) which some may not consider to be safe.
See: https://en.wikipedia.org/wiki/Google_Chrome#User_tracking

Question 6

how did you guys learn all of this stuff and teach it?

Accepted Answer

easy,watch the video closely. also don't enter thing that pop up randomly

Question 7

In my reading and studying, I keep coming upon the term "port", and these ports seem to play a pivotal role in the internet. Could someone explain these to me?

Accepted Answer

Ports are used by the computers to transmit data.

You can imagine them like a mailbox. One computer sends a packet to a receiver computer's "mailbox". Then, the receiver sends out a packet using that same "mailbox".

Different protocols and applications use different port numbers (there are thousands and thousands of port numbers).

If you want to really study the Internet (and just networking in general), I would suggest that you watch Professor Messer on youTube, specifically his Network+ playlist.
https://www.youtube.com/playlist?list=PLG49S3nxzAnnXcPUJbwikr2xAcmKljbnQ

Code.org

Course: Code.org > Unit 1

Learn more about the Internet on Khan Academy

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