Part 4 Hypertext Markup Language
Web pages are rendered in HTML for modern pages. We format text with tags enclosed in angle brackets to format the text. Tags are in pairs for opening and closing.
There are single tags such as <hr/> for horizontal closing.
Required tags – every page has a set of required tags to display a page accurately.
This section goes through the list of all html tags, I won’t cover all of them here. Check out https://www.w3schools.com/html/default.asp for more information.
Style Sheets
Web pages can use CSS (cascading style sheets) for advanced styling. This can be specific or global styles.
Part 5 Locating Info on the World Wide Web
Information is organized by different classification levels. Through the web page URL you can find out the file explorer page for each of the files.
Searching for Info – A search engine is a collection of computer programs that can help us find information across the web.
How a Search Engine Works
The first step is called crawling… As the crawler looks through the pages it builds an index.. This is a list of tokens that are associated with the pages. The second step is query processing. The user presents tokens to the query processor – the software that processes queries. The crawler considers almost anything followed by a space or punctuation a token.
Multi-word Indexed Searches
When searching multiple words this presents a “AND” query to accomplish this the query processor simply fetches the lists and intersects them, meaning the query processor finds which URLs are on all the lists.A web crawler still finds the Anchor text for the hyperlink in an HTML tag.
Page Rank
The order of the hits by the page. Google pionerneed this to be the page that has the most hits related to what you are looking for. It works like a voting system where it a page links out to another then it increases it’s importance.
Part 6 Online Research
Don’t assume everything is true on the internet. Haha, pretty funny that this is the only thing I had written in my notes.
Part 7 Debugging
Precision is everything. Input structure, common keys, upper/lower case. Debugging 0 figuring out a process or why a system doesn’t work. A workaround is used a commonly for everyday software with a new version is released.
Start debugging by trying to replicate the problem. Then determine exactly what the problem is.
Reproduce. Understand the problem. Check the obvious.
Part 8 Representing Info Digitally
Bit is the lowest level of representation that computers can read. It’s either a 0 or a 1.
1 byte is equal to 8 bits
It was changed from bite to byte, so that no single character change can create bit or vice versa
Part 9 Principles of Computer Ops
Computers deterministically perform or execute instructions to process information. The execute instructions based on the code that written.
Fetch/Execution Cycle – Getting instructions, gathering data, getting the result and then repeating
- Instruction – Fetch
- Instruction – Decode
- Data – Fetch
- Instruction – Execute
- Result – Return
Computer Anatomy
Memory – Random Access Memory
Control unit – The computer is the hardware implementation of the fetch/execution cycle
ALU(Arithmetic/Logic Unit) – Performs the math
I/O units – Are the data sources and an accessory to the computer
Chapter 10 Algorithm Thinking
5 Properties of Algorithms
Input Specified – Input is the data to be transformed. We must specify the data type and format.
Output Specified – Is the data resulting from computation. A possible output is no output
Definiteness – means specifying the sequence of operations for transforming the input into the output
Effectiveness – Means when those instructions can be executed
Finiteness – means anything will eventually stop
Language in Algorithms – Languages differ from agent to writer
Program vs Algorithm – A program is an algorithm that has been customized to solve a specific task
Chapter 11 Representing Multimedia Digitally
Digitizing Color – Each of the RGB colors is assigned a byte to record the intensity of that color
Binary and Decimal Numbers –
Digitizing Sound
The vibrations being pushed are transmitted, intensity of the push, determines the volume and the frequency. The key is that the object vibrates, continuously changing wave which is called analog information.
Analog to Digital – To digitize continuous information we must convert it to bits.
Sampling – We sample which means that we take measurements at regular intervals… The number of samples in a second is called a sampling rate.
MP3 compression – This removes the frequencies that are to low or high for us to hear.
Challenges
Latency – The time it takes for information to be delivered
Bandwidth – Closely related is bandwidth a measure of how much information can be transmitted in a unit of time
Christopher Sandoli 
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