AP CSP Unit 2 Test Review (Part 1)

Who created the internet? What was its early version called?

Bob Kahn and Vint; the internet was initially called ARPANET.

Why was ARPANET initially created?

It was a research project for the Department of Defense to build a communication system that could survive nuclear attacks.

How did the ARPANET initially work (Internet works this way too)?

It involved breaking up messages into blocks and sending them as quickly as possible through every possible direction in a mesh network.

What is a Mesh Network?

A type of network where each device (or node) is connected to several other devices directly, ensuring that even if one connection fails, the data can take other paths to get to the destination too.

Is there a single main controller managing the entire Internet?

No, because the internet is made up of millions of smaller independent networks that are all interconnected

What does an Internet Service Provider (ISP) do?

Allows people and businesses to access the internet via cable or wireless signals, and the ISP sends your data to the correct destination and brings that destination's data back to you.

What is an IP Address?

A unique number assigned to every device on the internet, ensuring information is sent to and from the right device.

In what format is everything on the internet sent in?

It's all sent in Bits.

What are the 3 main ways information is sent as bits across the internet?

• Electricity

• Light

• Radio Waves

What are the pros and cons of Electricity?

Pros: It's cheap.

Cons: There can be signal loss.

What are the pros and cons of Light?

Pros: Fast & no signal loss.

Cons: Expensive & hard to work with.

What are the pros and cons of Radio Waves?

Pros: Allows for mobility.

Cons: Has a short range.

How many bytes are in a Kilobyte?

1024 bytes

How many kilobytes are in a Megabyte?

1024 kilobytes

Bandwidth

The maximum transmission capacity of a device, measured in bitrate, or the number of bits that can be sent over a period of time, usually in seconds.

Latency

The time it takes for one bit to travel from one place to another.

Computing Device

A machine that can run a program, includes computers, tablets, servers, routers, and smart sensors.

Computing Network

A group of interconnected computing devices capable of sending or receiving data.

Computing System

A group of computing devices and programs working together for a common purpose.

Path

The series of connections between computing devices on a network starting with a sender and ending with a receiver.

Protocols

A well-known set of rules and standards agreed upon by all devices for communication.

How are IP addresses used in sending and receiving data?

When the sender sends data, they provide their IP address along with the receiver's IP so the Receiver can send the information back to the correct sender.

What is IPv4?

A system used to assign IP addresses that allows devices to have over 4.3 billion unique IP addresses, all in 32 bits.

Why was IPv4 retired?

It couldn't provide enough IPs to account for every device today.

What is IPv6 and why is it better than IPv4?

It's an even bigger system that uses 128-bit IP addresses and can assign over 340 undecillion unique IPs.

What is a Domain?

A website.

What does the Domain Name System (DNS) do?

It translates domain names like "www.google.com" into IP addresses that computers can use to communicate, which is provided by the DNS server.

How do DNS servers handle requests from multiple different devices to multiple different webistes?

They use a distributed hierarchy where each DNS server covers major domains like ".com" or ".org"

Why is the DNS vulnerable to cyberattacks, and name one example of a cyberattack?

DNS was initially designed to be an open, public communication protocol, which makes it vulnerable to hacks like DNS Spoofing.

What is DNS spoofing?

When a hacker taps into a DNS server and changes it so that domains (websites) point to imposter websites.