HTML, CSS and JS are inherent to all websites and represent the parts that clients interact with directly.

HTML is the code of the page, it is the language that includes tags <div>, <href>, <frame> and text. Once the code is written, you obtain a page on which you can find all our information, the website at this stage does not include a layout or UI design, it is a "barebones" website.

CSS is a language that will format the information int he HTML, it is the first graphic design stage, since we integrate all the elements of the brand's style at this point. At this stage in the website's development, it is attractive but does not yet have UX design that includes button ergonomics and style effects.

Javascript enables us to add effects to increase the dynamics of the website, particularly the buttons, menus, images / pictograms / purchase funnel, etc... It is the stage where UI design is developed.

What is a Web error?

In IT, HTTP code determines the result of a request or indicates an error.

There are 5 major groups of Status codes:

• 1xx: information
• 2xx: success
• 3xx: redirection
• 4xx: web client error
• 5xx: server / application server error

The ones you may encounter as a client are the following:

• 401: user not identified
• 403: access refused, you do not have sufficient rights to access the information requested
• 404: Page not found
• 500 and 503: server error, contact your host
• 504: the server is unresponsive, contact your host if this lasts

Landing page optimisation is a transversal issue in digital marketing as it affects most digital marketing tools. Through this tool, a simple "click" can turn into a prospect or even a client.

This stage should not be neglected to avoid a high bounce rate. This page presents the value proposition or the advantages of the offers advertised. The landing page can be a page on the website or a contact form, to avoid redirecting a landing page to an external page.

Optimising landing pages means proceeding to A/B testing or multivariate tests.

All developers aims to produce Web content, therefore HTML and CSS, regardless of the language used.

HTML

it is the hypertext language that is the building block of the Web. It is seen in the tags on the pages' blocks and represents what is in them.

example: title tag or text tag, picture tag...

CSS

100% the style of the page

example: colour, character, style effect...

A web service is a computer system interface protocol in the Web technology family enabling the communication and exchange of data between different applications and systems in distributed environments. It is a collection of functions available on the internet or intranet by and for applications or machines, without human intervention, in a synchronised or desynchronised manner.