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)
Identify the device on the network that can connect multiple devices and automatically assign them an IP address
Router
Describe what is meant by a dynamic IP address
- It can be used to uniquely identify a device (on a network)
- It can change …
- … each time the device is connected to the network