THE INTERNET PART 1 REVIEW Bits and Binary

THE INTERNET PART 1 REVIEW

Bits and Binary ■ Binary number system ■ A binary digit is a bit ■ Eight bits is a byte

Why binary? Currently, it’s cheaper and more reliable to design computers that only need to distinguish between two states! The 1 and 0 represent the on and off state of a transistor – a small electrical switch in a computer’s microprocessor!

How’s it work? Everything on a computer is represented as streams of binary numbers. Audio, images and characters all look like binary numbers in machine code. These numbers are encoded in different data formats to give them meaning, e. g. the 8 -bit pattern 01000001 could be the number 65, the character 'A', or a color in an image. This is why we have different file extensions! (. doc, . mp 3, . jpg

Encoding TEXT Binary - > Decimal - > ASCII

ASCII characters can be represented by binary numbers. According to ASCII character encoding, which of the following letters is represented by the 8 -bit binary value: 0100 0001 ? A. ASCII Character: A B. ASCII Character: B C. ASCII Character: D D. The table does not contain the value represented by the binary number 0100 0001

Binary and Storage ■ To double the amount of items you can store on a computer, you add a bit! ■ Notice the progression: – 1, 2, 4, 8, 16, 32, 64, 128, 256… – Each additional bit represents double the number of the previous!

OTHER Numeric Representations ■ In addition to binary (base 2), you may see decimal numbers (base 10) to represent RGB (Red, Green, Blue) values of color in Photoshop, or hexadecimal (base 16) to represent colors on websites. ■ However, all of these are eventually encoded as binary when processed by the computer.

Number systems with different bases such as binary (base-2), octal (base-8), decimal (base-10), and hexadecimal (base-16), are all used to view and represent digital data. Which of the following is NOT true about representing digital data? A. At one of the lowest levels of abstraction, all digital data can be represented in binary using only combinations of the digits zero and one. B. The number system you use to view data has no effect on the underlying digital data. C. Binary can be used to represent more complex, higher level abstractions, including but not limited to numbers, characters, and colors. D. When data is large enough computers switch to using decimal representation instead of binary, because you can represent larger numbers with fewer digits.

Transfer of bits over the Internet ■ Two factors affect this transfer: – Bandwidth: The size of the packet of bits being transferred in bits– these days, it’s common to measure bandwidth in Mbps (megabits per second) – low bandwidth means smaller packets; high bandwidth means larger packets. – Latency or delay: How many milliseconds (ms) it takes for a packet of bits to reach its destination – low latency means it takes less time; high latency means it takes more time!

A. B. A user clicks on a website, and it begins to load immediately, but it takes a long time to load completely and pictures appear slowly, one by one. Which of the following is demonstrated through this situation? High bandwidth, high latency Low bandwidth, high latency C. D. High bandwidth, low latency Low bandwidth, low latency

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