2. ISP and Browsers

ISP stands for 'Internet Service Provider'.

An ISP is a company that provides access to the internet for business and individuals.

They usually charge a monthly fee for this service. You usually enter a legal contract with them that sets out what you can and cannot do.

For example there may be data download limits, especially on mobile connections. There is usually a 'fair use' clause that does not allow any unethical or illegal use of the service - hacking for example.

They will issue you with a user name and password and very often an email address.

For individuals, the ISP normally provides a modem through which you can log in and access the internet via one of the ISPs servers.

Web Browser

The web browser is the main software application used to access the web. To display a specific web page, it makes a set of requests to the web server to send it all the files needed to construct the page, including its styling files (css), its content (html), any media content (video), any code scripts (javascript) and any stored data (cookies). Once they are available, the page is rendered on screen.

To save time rendering the same page later on, many of the files are stored in the browser cache so that they are immediately available once more without having to fetch them from the server again.

There are quite a few browsers available. These include Chrome, Firefox, Safari, Edge and so on. There are also specialist browsers or screen readers available to help blind or visually impaired people. As the person explores the page, it speaks out the content.

To improve accessibility, web designers should use 'semantic' html5 mark-up that describes the purpose of each section of the page such as <nav> </nav> to indicate a navigation area. The ARIA (Accessible Rich Internet Applications) specification sets out a list of html elements that describe each part of the page to a screen-reader. For example an input box can be coded like this

<input type="text" aria-label="User Name">

where the mark-up 'aria-label' is explaining the purpose of the input box to a screen-reader.