Informática (Ingles)

Guía de informática

History of internet
* Before internet there was the idea that several computers could be linked together so they could “talk” this network was called DARPANET.
WWW
* www World Wide Web
* internet existed before WWW
* The www is only part of the internet.
* The internet and the www work together but are not the same

Internet Web
Providesinfrastructure provides interface that the user interacts with
Web – history
* Websites are written in a language called HTML
* Originally:

* Tools to write HTML where: primitive and relied heavily on programming knowledge
* Basic website structure had: headings, paragraphs, ability to link using hyperlinks
Web browser special software for viewing web pages and documents onthe internet or on a network intranet.
Examples: Mozilla firefox
Windows internet explorer
Opera
Names and addresses: each divide connected to a network has a unique IP address or DNSS name.
IP address: shown as four decimal numbers separated by full stops.
Example: 192.188.20.1
DNS: has two or more parts separated by dots and typically consist of some form of an organization’sname and a three letter or more suffixes.
Example: www.sample.com
The domain names suffix describes the type of organization:
Suffix | Description |
.net | For networks, usually reserved for organizations such as internet service providers |
.org | For non-commercial organizations |
.edu | For educational institutions and universities. |

Country codes:
Examples: .au – Australia.jp-Japan .uk – United Kingdom
Developments of the WWW
The systems that work together provide a new way of communication for the users and provide a new way to conduct human day to day life.
* Online shopping
* Communication with friends
* Information sharing
* Online banking
* Online recruiting sites
* Online news
* Online entertainment (movies,music, etc)
E-commerce: consist of the buying and selling of products or services over the internet. Like: electronic funds transfer or online marketing.
Examples of E-Shops: eBAY Mercado Libre Amazon
Chat rooms: online chats are a way of communication by sending text messages to people In the same chat-room in real-time.
Social networking:
Examples: youtube facebook twitter MySpaceWeb constraints
Website designs include elements such as:
Content, graphics, animation, font, colour selection, navigation design, HTML and javascript.
Therefore there should be a limit to how much is included in a website. Technical issues in website design are:
1) Bandwidth constraints:
This refers to the amount of data that travels in one second between the computers where your websiteis located (web server) and the visitor’s computer.
The speed in which your website will display on your monitor will depend on the content and size of each web page.

2) Screen resolution:
This is the measure of number of pixels (dots) that your screen is set to display. The screen resolution used will depend on the size of the monitor.
Currently web developers design and develop websitesto comply with 1024 x 768 pixels.
3) Colour palette:
The web-safe colours that should not dither on computer display system can only display 256 colours (also known as 8-bit colours) and will display on MAC and PC computers.
4) Browsers compatibility and restriction:
The best way to deal with cross browser compatibility issues is to design your website using the right tools and usingHTMLA that uses standards compliant code (using correct tags for elements).
* Plugins: small pieces of computer code that extend a web browser to view data formats other than HTML and images.

5) Font availability:
Ensures that you always use system fonts e.g. arial, verdana, etc..
6) Font size:
Most browsers allows users to custom their default sixe, the user preference may cause...