Connecting to the Internet (Edexcel IGCSE ICT)

Web browser

What is a web browser?

• A web browser is a software application used to locate, retrieve, and display content on the World Wide Web (WWW)

• Web browsers are used to display web pages which include images, videos and other files

• Most web browsers have the following features:

  • Home page

  • Ability to bookmark favourites

  • Keep a history of visited websites

  • Hyperlinks which allow users to navigate between pages

Internet Service Provider (ISP)

What is an ISP?

• An Internet Service Providers (ISP) is a company that provides access to the Internet to users and businesses

• The ISP provides internet access by leasing equipment and telecommunication lines to users that are required to access the internet

• IPS generally charge a subscription fee for access to the internet

Search Engines

What are Search Engines?

• Search engines are tools that locate and display web pages related to the search terms entered by the user

• They are essential for navigating the vast amount of information on the internet

• They index millions of web pages and use algorithms to rank the relevance of each page to the search terms

How do search engines work?

• Search engines work in several stages:

  • Crawling

  • Indexing

  • Ranking

• Crawling is when web crawlers scour the internet daily to retrieve new websites

• Indexing is how websites are categorised based on the content of their web pages, keywords and metadata

• Ranking is how websites are ranked and listed on search engine pages - this depends on many factors to display the most relevant results

Filter software

What is filter software?

• Filter software uses two lists stored in a database to allow or block access to websites

• URLs entered by a user are compared against both lists

• The two lists are:

  • Whitelist - URLs on the whitelist are allowed and the website can be viewed

  • Blacklist - URLs on the blacklist are not allowed and the website is blocked

• URLs that cannot be found on either list are allowed

• Filter software is used by schools and parents to protect children from accessing age inappropriate content

• Administrators can add and remove URLs from the lists