The Internet Flashcards
fault tolerance
a process that enables an operating system to respond to a failure in hardware or software
what is the internet?
● A philosophy of making information and
knowledge open and accessible to ALL
● A network of networks
● Built on open, agreed upon protocols
the internet…
- is decentralized
- has a high fault tolerance
- is scalable
decentralized
controlled by several local offices or authorities rather than one single one
computing device
- object that can run a program
- ex. computer, tablets, servers, routers
computing system
group of computing devices and programs working together for a common purpose
computing networks
- a group of interconnected computing devices capable of sending or receiving data
- type of computing system
path
the sequence of directly connected computing devices that begins at the sender and ends at the receiver
routing
- the process of finding a path from sender to receiver
- dynamic (not pre decided)
bandwidth
- the maximum amount of data that can be sent in a fixed amount of time
- usually measured in bits per second
modem
Allows Computers to talk to
one another over telephone
lines
how to organize data
- Chunk your data into pieces: packets
- Individually route the packers on the most efficient path
packets have…
metadata
**Who is sending the
data, Where are the
sending it, Instructions for
reassembling the
data
packets might arrive….
In order, Out of Order, Not at all
protocols
- agreed-upon set of rules that specify the behavior of a system
- open and available to everyone
internet protocol (IP)
a set of standards for addressing and routing data on the Internet
IPv4 vs IPv6
- IPv4: 32-bit address; est. 1981; 4.3 billion possible addresses; ex. 192.168.1.1
- IPv6: 128-bit address; est. 2012; 340 undecillion possible addresses; ex. 2001:0db8::1
when to use TCP
- When things need to be perfect
- Used for programs, emails, webpages
- Doubling network traffic
transmission control protocol (TCP)
- designed to send packets across the internet and ensure the successful delivery of data and messages
- uses packet switching
- finds the most efficient pathways
- Makes sure files are downloaded completely and correctly
- Adds its own header to packets
- Requires an acknowledgement OR it resends
internet service provider (ISP)
- your IP address is assigned to you by your ISP
- your internet activity goes through the ISP, and they route it back to you, using your IP address.
IPv4
- IPv4: 32-bit address; est. 1981; 4.3 billion possible addresses; ex. 192.168.1.1
IPv6
- IPv6: 128-bit address; est. 2012; 340 undecillion possible addresses; ex. 2001:0db8::1
user datagram protocol (UDP)
- When speed is more important than perfection
- Adds header information
- Destination computer does not acknowledge receipt of packets
- Faster but risks dropped packets
hypertext transfer protocol
- Used for accessing web pages
- Hypertext documents contain texts with links
- HTTP send information back in plain text
- HTTPS = encrypts
- S stands for SSL protocol (Secure Sockets Layer)
domain name system (DNS)
- Service that maps IP addresses to their domain name
- Instead of 216.58.216.142 you can type testout.com
- DNS server looks up the IP address and sends it back to the host computer
world wide web vs. internet
WWW - the pages you see when you’re at a device and you’re online
internet - the network of connected computers that the web works on, as well as what emails and files travel across
***The Web uses The Internet
sequential computing
computational model in which operations are performed in order one at a time
parallel computing
computational model where the program is broken into multiple smaller sequential computing operations, some of which are performed simultaneously
computer processing unit (CPU)
the CPU follows, or executes, each line of the computer program in order, turning the data from the user into information. This is called processing.
cores
- physically separate processing units on the same CPU
- allows for parallel processing
**e-cores = efficiency
**p-cores = performance
threads
- Creates virtual separate processing units on the same core
distributed computing
computational model in which multiple devices are used to run a program
comparing efficiency of solutions
can be done by comparing the time it takes them to perform the same task.
sequential solution
takes as long as the sum of all of its steps
parallel computing solution
takes as long as its sequential tasks plus the longest of its parallel tasks
parallel computing
- Parallel computing consists of a parallel portion and a sequential portion
- can scale more effectively than solutions that use sequential computing
- When increasing the use of parallel computing in a solution, the efficiency of the solution is still limited by the sequential portion. At some point, adding parallel portions will no longer meaningfully increase efficiency.
distributed computing
- allows problems to be solved that could not be solved on a single computer because of either the processing time or storage needs involved
speed-up of parallel solution
time for sequential processing / time for parallel processing
