5.1 & 3.4 The Internet and the WWW & Network Hardware Flashcards
What is the difference between the Internet and World Wide Web?
- The Internet is a global infrastructure of interconnected networks …
- … uses transmission protocols (TCP) and internet protocols (IP)
- The World Wide Web is only a part of the internet that users can access using web browser software …
- uses http/https protocols
- The World Wide Web uses the Internet to access information from web servers
Internet or WWW?
- Users can send and receive emails?
- Uses the internet to access information from web servers?
- Web resources are accessed by web browsers?
- Allows online chatting (via text, audio and video)?
- Makes use of transmission protocols (TCP) and internet protocols (IP)?
- Uses the http(s) protocols and the hypertext mark-up language (HTML)?
- It is a worldwide collection of interconnected networks and devices?
- Uniform resource locators (URLs) are used to specify the location of web pages?
Internet or WWW?
- Users can send and receive emails? Internet
- Uses the internet to access information from web servers? WWW
- Web resources are accessed by web browsers? WWW
- Allows online chatting (via text, audio and video)? Internet
- Makes use of transmission protocols (TCP) and internet protocols (IP)? Internet
- Uses the http(s) protocols and the hypertext mark-up language (HTML)? WWW
- It is a worldwide collection of interconnected networks and devices? Internet
- Uniform resource locators (URLs) are used to specify the location of web pages? WWW
What is a web browser?
- Software that enables users to access resources on the WWW
- It contains an address bar where the user can enter a URL
What are the functions of a browser?
- Software that enables users to access resources on the WWW
- It contains an address bar where the user can enter a URL
What is HTTP?
- Hypertext Transfer Protocol
- A protocol that defines how messages are transmitted and formatted over the World Wide Web
Describe what is meant by HTTPS
- Hypertext Transfer Protocol Secure
- A protocol that defines how messages are transmitted (securely) and formatted over the World Wide Web
- It means data sent to and from the web server is encrypted
- A locked padlock is shown in the browser
- It means a website uses TLS/SSL
What is a protocol?
- A set of rules that define how devices communicate e.g. HTTP
What is a URL?
- Uniform Resource Locator
- The website address typed into a web browser
- Made up of Protocol, Domain name & file name e.g https://www.bbc.com/index.html
Identify the 3 main parts that make up a URL
https://www.bbc.com/news/uk/index.html
- Protocol e.g. https
- Domain name e.g. www.bbc.com
- File name and path e.g news/uk/index.html
What is meant by a fully qualified domain name?
A fully qualified domain name contains both a
- Domain host e.g. www
- Domain name e.g. bbc.com, apple.com
It can also be broken down further
- Domain type e.g. .com, .gov, .org
- And sometimes a country code e.g. ,uk, .de
Describe what is meant by Domain Name
- A web servers name.
- Each domain name is unique.
- Used to identify IP addresses.
Describe what is meant by ISP?
- Internet Service Providers
- Companies that provide the user with access to the internet e.g. Virgin, BT, Sky
Describe what is meant by DNS
- Domain Name System
- Internet service that translates domain names into IP addresses
Describe how a DNS server works
- Contains a database of IP addresses
- When you request an address (URL) …
- …it looks up the URL in a table and …
- …returns the corresponding IP address
- …or searches for the address from another server
What is a web server?
- Device that responds to requests to provide information and services over the world wide web
- Distributes web pages (and other resources) as they are requested
Give 3 examples of a server other than a web server
- File server
- Email server
- Print Server
How does a web browser use the URL to access a web page
- Web browser sends URL to DNS server
- IP address sent back to web browser
- Web browser sends request to IP address of web server
- Web server sends web page to web browser
- Web browser interprets HTML and displays the web page
What is a a NIC?
- Network Interface Card
- connects a computer to a computer network
- formats the data sent from the computer into a required format according to the protocols (rules) of the network e.g. TCP/IP.
- Each NIC has a unique ID known as a MAC address assigned to it
Describe what is meant by a MAC address
- Media Access Control
- Unique ID assigned to a Network Interface Card
- Hardware address - assigned by a manufacturer
- It does not change
- 12 Hex digits e.g. 3A-34-53-C4-69-B8 (First 6 digits Manufacturer ID, Last 6 digits Serial Number)
Describe what is meant by an IP address
- Internet Protocol address
- A unique address for each device on a network / the Internet
- Software address - allocated by the network
- It can be
- static (does not change)
- dynamic (can change)
- Two versions
- IPv4 (32 bit/4 bytes e.g. 172.16.254.1)
- IPv6 (128 bit/16 bytes)
- It can be
- private (used on a local network)
- public (used by a device on the internet)
What are cookies?
- Small packets of data
- Browsing data stored in a text file
- Stored by the browser on users computer
- Used by the website when it is visited again
State 2 different types of cookies
- Session Cookies
- Persistent Cookies
Explain the difference between a session and persistent cookie
Session cookies
- Stored in temporary memory
- No longer exist when the browser is closed
- e.g. virtual sh_____ bas____
Persistent cookies
- Stored on a users hard drive until deleted or expires
- Still exist even after the browser is closed
- Websites should encrypt any personal information
- e.g. user’s log in details
True or False?
- Cookies can be used to store a user’s credit card details
- Cookies can be used to track the items a user has viewed on a website
- Cookies will corrupt the data on a user’s computer
- Cookies are downloaded onto a user’s computer
- Cookies can be deleted from a user’s computer
- Cookies are are sent to the website when you visit it gagain
True or False?
- Cookies can be used to store a user’s credit card details True
- Cookies can be used to track the items a user has viewed on a website True
- Cookies will corrupt the data on a user’s computer False
- Cookies are downloaded onto a user’s computer True
- Cookies can be deleted from a user’s computer True
- Cookies are are sent to the website when you visit it again True
Why do websites use cookies?
- to store personal information
- to store login details
- to save items in a shopping basket
- to customise web pages
- to track visited websites
- to carry out targeted advertising
- to store credit card details
What is HTML?
- Hypertext Mark-up Language
- A web authoring (mark up) language used to create web pages
- It is uses tags to define the structure e.g. h1, h2, p
- Note: it can be used for presentation/formatting, but normall CSS
What is CSS?
- Cascading Style Sheets
- Used for presentation
- Used so that formatting information does have to be included with the content and layout
- Style sheets hold the formatting information for particular tags e.g.
- h1 { color: blue; }
What are the advantages of CSS?
- Style only needs to be defined once and it is then applied to all instances .
- Only needs to be changed in one place
- Same style can be applied to many different documents
- Pages will load faster as there is less description
Why is HTML important?
- It is an accepted standard, so all browsers will display the data correctly.
- Enables a web browser to interpret a file and display the content
Describe the use of structure and presentation in a HTML document
- Structure (HTML) is used to create the layout
- Mark up tags are used to define the structure (although presentation can be included in the tag)
- e.g h1, h2, p
- Presentation (CSS) is used to format colour/style
- e.g. h1 { color: blue; }
- Structure and presentation are often kept separate making it easier to update the style
- A CSS file is linked to a HTML document to define the style of the entire page
What is external CSS?
CSS: Cascading Style sheets
Seperate CSS files for presentation allow changes to a website style/formatting to only be made in one place.
What is a a NIC?
- Network Interface Card
- connects a computer to a computer network
- formats the data sent from the computer into a required format according to the protocols (rules) of the network e.g. TCP/IP.
- Each NIC has a unique ID known as a MAC address assigned to it
Describe what is meant by a MAC address
- Media Access Control
- Unique ID assigned to a Network Interface Card
- Hardware address - assigned by a manufacturer
- It does not change
- 12 Hex digits e.g. 3A-34-53-C4-69-B8 (First 6 digits Manufacturer ID, Last 6 digits Serial Number)
Describe what is meant by an IP address
- Internet Protocol address
- A unique address for each device on a network / the Internet
- Software address - allocated by the network
- It can be
- static (does not change)
- dynamic (can change)
- Two versions
- IPv4 (32 bit/4 bytes e.g. 172.16.254.1)
- IPv6 (128 bit/16 bytes)
- It can be
- private (used on a local network)
- public (used by a device on the internet)
What is a router?
- A piece of network hardware
- It has 2 IP addresses
- Uses IP addresses to send data packets from router to router
- Uses routing algorithms to determine optimum route for data packets
- Connects 2 or more networks e.g. between a local network and the Internet
- Converts the data to a protocol understood by different networks
Static or Dynamic IP address?
- They allow each device to be fully traceable
- Greater privacy since they change each time a user logs on
- Less reliable as it can disconnect and change the IP address
- Allow for faster upload and download speeds
- More expensive to maintain since the device must be constantly running
Static or Dynamic IP address?
- They allow each device to be fully traceable (Static)
- Greater privacy since they change each time a user logs on (Dynamic)
- Less reliable as it can disconnect and change the IP address (Dynamic)
- Allow for faster upload and download speeds (Static)
- More expensive to maintain since the device must be constantly running (Static)
MAC address or IP address?
- Identifies the global address on the internet
- May not necessarily be unique
- Identifies the physical address of a device on the network
- Assigned by the manufacturer of the device and is part of the NIC
- Unique for device on the network
- When a packet of data is sent and received, the MAC address is used to identify the senders and recipient’s devices
- Use 48 bits
- Used in routing operations as they specifically identify where the device is connected to the internet
- Use either 32 bits (IPv4) or 128 bits (IPv6)
MAC address or IP address?
- Identifies the global address on the internet (IP)
- May not necessarily be unique (IP)
- Identifies the physical address of a device on the network (MAC)
- Assigned by the manufacturer of the device and is part of the NIC (MAC)
- Unique for device on the network (MAC)
- When a packet of data is sent and received, the MAC address is used to identify the senders and recipient’s devices (MAC)
- Use 48 bits (MAC)
- Used in routing operations as they specifically identify where the device is connected to the internet (IP)
- Use either 32 bits (IPv4) or 128 bits (IPv6) (IP)
True or False?
- A MAC address is unique to a computer on a network
- Once an IP address has been set it cannot be changed
- A MAC address is made up of the computer’s serial number and the IP address
- If a computer does not have an IP address it cannot communicate with another device using the Internet
- An IP address can be used instead of a URL
- A MAC address is allocated by the network
- IP addresses and MAC are addreses are both unique
True or False?
- A MAC address is unique to a computer on a network (True)
- Once an IP address has been set it cannot be changed (False)
- A MAC address is made up of the computer’s serial number and the IP address (False)
- If a computer does not have an IP address it cannot communicate with another device using the Internet (True)
- An IP address can be used instead of a URL (True)
- A MAC address is allocated by the network (False)
- IP addresses and MAC are addreses are both unique (True)