Layman's Guide to Computing

When a webpage document loads (Stage 1), it is processed by the web browser, which then

An HTML file contains markup tags that tell the browser how to interpret and format the text within the tags. Other document formats usually use tags in a similar way. These tags constitute a markup language that any app can use to mark up its own text too.

PDF is the gold standard for universal compatibility (supported by most software and platforms) and visual fidelity (displays exactly the same way). When you need things to appear on a different device in exactly the same way you created it, without having to install additional software, use PDF.

PDF’s markup language is more concerned with how things appear on the page than with what they were originally. Once the PDF is generated, it is almost impossible to retrieve the original data from it. Scanned documents that are converted to PDF may have a text layer generated by OCR that lets detected text be copied from it.

There are two ways your browser can send cookies back to the server:

Document databases organise data into documents, each containing a number of field-value pairs. Each value can itself be a document, and multiple values/documents can be grouped under a field. Document databases do not enforce data consistency across documents, so those rules need to be managed by the application which is using the database. This allows document databases to continue operating even when partitioned, at the cost of some consistency.

Graph databases treat the details of things as secondary, and optimise for managing the network of relationships. A graph database can quickly look up how things are related to each other, and return the results.