Jess Rolfe
DLA 112 - chapters 7 & 8 summaries
First year 2024
Chapter 7
The internet , intranets and extranets
Internet
• Worldwide collection of millions of computers and networks of all sizes
• It is basically a network of networks
The internet backbone
- is the foundation of the internet
- which support all other networks
- which form part of the Internet
World Wide Web (www)
• Graphical interface to the largely text-based internet in 1989
Hypermedia
• The web organises information by using hypermedia
• Documents that include embedded references to audio, text, images, video and
other documents
Hypertext
• Embedded references in hypermedia documents
• Links users can click to follow to a particular thread (topic)
Domain name system
• Unique identifiers of computer or network addresses on the internet
• IBM.com ; whitehouse.gov
Converts domain names to IP adresses
- when information is transferred from one network to another network
Domain names are used in
- the URL which identifies the address of a document or page
1
, Types of internet connections
Methods for connecting to network incl. internet :
→ dial up modems
→ cable modems
→ DSL - Digital Subscriber Line
Types of DSL services
• SDSL = symmetric
• ADSL = asymmetric
• VDSL = very-high speed
Navigational tools
What are navigational tools ?
• Used to travel from site-site or to “surf” the internet
Graphical Web browsers available :
→ microsoft internet explorer
→ mozilla firefox
→ google chrome
Search engines
Information system which enables users to extract data from the Web by searching for
information by making use of search terms
google.com
bing.com
3 step process
1. Search web
• Looks for updates/links ensures search engine has latest info
2. Indexing
• Keywords are searched
3. The search process
• Identify webpages with key words and places in order of priority
Directories
2 types of directories : organises information into categories
1. Automated directory
Creates directories automatically with search terms
If web pages change , the directory is automatically updated
2. Human-powered directory
Keywords need to be manually submitted before the webpage appears on the search
engine
2
DLA 112 - chapters 7 & 8 summaries
First year 2024
Chapter 7
The internet , intranets and extranets
Internet
• Worldwide collection of millions of computers and networks of all sizes
• It is basically a network of networks
The internet backbone
- is the foundation of the internet
- which support all other networks
- which form part of the Internet
World Wide Web (www)
• Graphical interface to the largely text-based internet in 1989
Hypermedia
• The web organises information by using hypermedia
• Documents that include embedded references to audio, text, images, video and
other documents
Hypertext
• Embedded references in hypermedia documents
• Links users can click to follow to a particular thread (topic)
Domain name system
• Unique identifiers of computer or network addresses on the internet
• IBM.com ; whitehouse.gov
Converts domain names to IP adresses
- when information is transferred from one network to another network
Domain names are used in
- the URL which identifies the address of a document or page
1
, Types of internet connections
Methods for connecting to network incl. internet :
→ dial up modems
→ cable modems
→ DSL - Digital Subscriber Line
Types of DSL services
• SDSL = symmetric
• ADSL = asymmetric
• VDSL = very-high speed
Navigational tools
What are navigational tools ?
• Used to travel from site-site or to “surf” the internet
Graphical Web browsers available :
→ microsoft internet explorer
→ mozilla firefox
→ google chrome
Search engines
Information system which enables users to extract data from the Web by searching for
information by making use of search terms
google.com
bing.com
3 step process
1. Search web
• Looks for updates/links ensures search engine has latest info
2. Indexing
• Keywords are searched
3. The search process
• Identify webpages with key words and places in order of priority
Directories
2 types of directories : organises information into categories
1. Automated directory
Creates directories automatically with search terms
If web pages change , the directory is automatically updated
2. Human-powered directory
Keywords need to be manually submitted before the webpage appears on the search
engine
2
