Yr8 Computing Notes: Revision

Yr8 Computing Notes: Revision

1. HTML

   • HTML – HTML is a technique to store and file things on a computer/the coding behind a website

2. WWW

   • WWW – WWW (world wide web) is a huge collection of websites all over the world

3. WEBSITE

   • WEBSITE – a WEBSITE is where you can find info about something - each website contains web pages which are navigated to via hyperlinks - websites are stored in web servers all over the world

4. What happens when I view a web page?

   • Your computer -> Your ISP -> Internet -> Website host/server
     • Website host/server links/sends the info back to your computer

5. DNS

   • DNS – DNS stands for Domain Name System; the phone book of info online

6. ISP

   • ISP – ISP stands for Internet Service Provider - Name > Number - The ISP tells the IP address to send the info requested by the browser to the browser

7. What is a Responsive Website?

   • A responsive website is a website that adjust to the size of the screen/browser that the website is being produced on

8. Steps to gather info when you are constructing a web page

   • 1) Idea (subject) 2) Gather info – about on your idea 3) Designing – Design the page to the right age appropriate of your idea
     •  1)Idea (subject)  2) Gather info – about on your idea 3) Designing – Design the page to the right age appropriate of your idea

9. CSS

   • CSS stands for Cascading Style Sheet and is used by web pages to help keep information in the proper display format. CSS files can help define font, size, color, spacing, border and location of HTML information on a web page, and can also be used to create a continuous look throughout multiple pages of a website.

10. Python

    • Debug - debugging is correcting an incorrect error. When you are using python if you make an incorrect code, the screen will show SYNTAX ERROR.
      • Cyntax Error
        • Computer bugs refer to an error in the program. A software bug is an error, flaw or fault in a computer program or system that causes it to produce an incorrect or unexpected result, or to behave in unintended ways. A few are caused by compliers producing incorrect code
    • Slicing - You can return a range of characters by using the slice syntax. Specify the start index and the end index, separated by a colon, to return a part of the string.
      • E.G. b = "Hello, World!" print(b[6:12]) it would print world the first letter (in this case H) is always 0
      • You do the exact same for lists!
        • E.G. list = "Banana, Papaya, Strawberry, Mango" print(list[8:26]) it would print Papaya, Strawberry
      • Negative slicing - this is when you do slicing but start from the end of the words.
        • E.G. list = "Banana, Papaya, Strawberry, Mango" print(b[-26:-7]) it would print Papaya, Strawberry it would print this because you are going backwards from mango this time.

11. Algorithm

    • The different steps in order to solve the problem. An algorithm is a set of instructions designed to perform a specofoc task. This can be a simple process, such as multiplying two numbers, or a complex operation, such as playing a compressed video file. In computer programming, algorithms are often created as function.
      • E.G. The set of instructions of solving the problem of frying eggs: 1) Get the frying pan 2) Put the pan on the hob 3) Turn on the hob 4)Put oil on the pan 5) Hold egg over pan 6) Break egg 7) Show produce

12. Decomposition

    • Decomposition is one of four cornrstones of computer science. It involves breaking down a complex problem or system into smaller parts that are more manageable and easier to understand. The smaller parts can then be examined and solved, or designed individually, as they are simpler to work with.

13. Variables

    • A variable is a location in memory in which you can temporarily store text or numbers Once the program is running, it is there but once it is stopped or closed it is deleted and paused
    • Rules for running a programme
      • The name can only contain numbers letters and underscores  It cant start with a number  You cant use a python ‘reserved word’ as a variable name  To make your programs easier to understand, use meaningful names for your variables 
    • Functions
      • Functions are special built in routines that do a specific job  They appear in purple   When a code doesn’t work it will come up with syntax error  Debug is to edit your coding   If you want to print out a long paragraph you have to put three quotation marks  Strings behave as a list or an array  A space is an element as well  If you want to print just one letter you have to put   Eg our wonderful = to print the letter o u put 0 because it is the first element - print(a [0]) -----first element is 0   To print the letter U you put the number 1 because it is the second element – print(a[1])  Each letter is an element

14. Cyber crime

    • Email scams
      • Phishing
        • There is usually a sense of urgency
        • Definition - the practice of sending fake emails to reveal personal info like passwords
      • Trojan Horse - Offers something tempting to look at, either an attachment or link for example a funny video
      • When you open the attachment or click the link, it installs the virus on your computer
      • The virus might:
        • - Record your keystrokes and send them to the attacker - Provide someone else with access to your files - Use your computer to send a spam to everyone in your address book
    • Cyber security
      • Often confused with Information Security
    • Types of malware are; viruses, worms, trojan horse, spyware, ransomware
      • viruses wormstrojan horsespyware ransomware