CSP Unit 1 Latest Update with Certified Solutions

CSP Unit 1 Latest Update with Certified Solutions computer science The study of information and information processes Binary A way of representing information with only 2 options Binary question A question with only 2 possible answer options Binary message A message that only has one of 2 possible values Protocol A set of instructions for completing a task Bit A single unit of information, 0 or 1 Bit rate The number of bits transmitted per second ASCII American Standard Code for Information Interchange, universally recognized text format, translates letters to numbers How many bits represent each ASCII character? 8 Internet Engineering Task Force IETF, develops standard guidelines for using the Internet, particularly the standards for TCF/IP Internet A group of computers connected to one another, a tangible system made to move information IP address Internet Protocol address, a number assigned to any device connected to the Internet. Packets Small chunks of information that have been formed from larger chunks of information Router A server that directs packets based on the IP address inside the packet Why is redundancy important in routing? Redundancy means there are multiple paths for information to follow. This is important because it allows the Internet to work efficiently. Transmission Control Protocol TCP, provides error checked, reliable, ordered delivery of packets on the Internet What does TCP do? TCP sends each packet on an individual path. Each packet arrives at a different time depending on traffic. When each packet is received, they are correctly order so that the message can be read. Domain Naming System DNS, translates human readable domain names into machine readable IP addresses Why do we need IP addresses? Computers speak in numbers, not letters and we need a "to" and "from" address for a mesaage T or f: A computer's IP address stays the same. F HyperText Transfer Protocol HTTP, system used for transmitting web pages over the Internet. ASCII text based protocol for sending and receiving web pages Client Computer that requests information Server Computer that accesses information and sends it back Abstraction One layer only needs to focus on its specific job, not the jobs of others. Relies on them, but does not need details of each IvP 4 IP addresses contained 32 bits, provides more than 4 billion unique addresses IvP 6 IP addresses contain 128 bits to accommodate the amount of devices on the Internet, provides 340 undecillian addresses Process of translating DNS to IP 1. User types in URL 2. Client connects to DNS server 3. Server matches URL to IP 4. Server pulls up website How are DNS servers split? Divided in a distributed hierarchy DNS spoofing Hackers tap into DNS server and changes it to an imposter website Latency The time it takes data to travel from one host to another Secure Sockets Layer SSL, provides a secure connection Transport Layer Security TLS, provides a secure connection 1 kilobyte= 1000 bytes 1 megabyte= 1000 kilobytes 3 physical ways to send bits Electricity, light, radio waves Bandwidth Maximum transmission capacity of a device, measured by bitrate How many bits are in a megabyte? 8 million Fiber optic cable Sends bits as light Electric Pro: Cheap Con: Signal loss Light Pros: Fast No signal loss Con: Expensive Hard to work with Radio waves Pro: Wireless Con: Signal loss Who controls the Internet? It is controlled by independently operated networks ISP Internet service provider Layers in order DNS TCP IP Physical internet T or F: Packets take different routes depending on traffic. T What does each packet have? The IP address of where it came from and where it's going Server vs router A server stores information for when it's requested. Ex DNS server A router moves information to where it needs to go. Fault tolerant Network can keep sending packets if something goes wrong because there are multiple routes. T or F: More router equals more reliability T Uniform Resource Locator URL GET request HTTP, asks for HTML code page you want HyperText Markup Language HTML T or F: The browser sends separate HTTP requests for each picture or video on the site T POST request HTTP, sends data to server Cookies Data held by web browser that tells server who you are Digital certificate Certificate that tells server that website is secure Layers: HTTP & DNS: Manage sending and receiving of web pages TCP & IP: Break data into packets and route them Physical Internet: Transmits messages