Digital Library Technology

Technology Used By Digital Libraries

As mentioned earlier, DELOS defines a digital library as one component of a three-part framework which also includes a digital library system, and a digital library management system. While those terms are frequently used interchangeably DELOS contends that each part of the framework plays a unique role within the ecosystem. The following illustration depicts the DELOS framework (Setting the Foundations of Digital Libraries: The DELOS Manifesto, n.d.)


The following table provides definitions from each tier.

Digital Library Digital Library System (DLS) Digital Library Management System (DLMS)
A possibly virtual organization that comprehensively collects, manages, and preserves for the long term rich digital content, and offers to its user communities specialized functionality on that content, of measurable quality and according to codified policies. A software system that is based on a defined (possibly distributed) architecture and provides all functionality required by a particular Digital Library. Users interact with a Digital Library through the corresponding Digital Library System. A generic software system that provides the appropriate software infrastructure both (i) to produce and administer a Digital Library System incorporating the suite of functionality considered foundational for Digital Libraries and (ii) to integrate additional software offering more refined, specialized, or advanced functionality.

If you are a little confused about how to distinguish between the tiers, you’re not alone. Here’s a tip. Compare it to Microsoft Access.

Microsoft Access is a relational database management system (DBMS) which software developers, data architects and database designers can use to develop application software and database systems. The applications and databases contain forms and reports which allow end users to access their contents. So, in comparison to the DELOS model, the MS Access application is the management system, any given database is the equivalent of the library software system, and forms and reports within the database are the equivalent of a digital library. This is not a perfect one-on-one correlation for functions but hopefully this gives you a clearer understanding of the terminology used when discussing digital libraries.

DELOS has defined six core concepts (illustrated below) which apply to digital libraries: user, content, functionality, quality, policy and architecture (Setting the Foundations of Digital Libraries: The DELOS Manifesto, n.d.)

Internet technologies are an integral part of digital library architecture. The DELOS “Architecture” concept refers to the Digital Library System and represents the way that the hardware and software components create the interrelatedness between the form, function and content of the Digital Library. It is the internet technology in the DLS architecture that allows users to click on a hyperlink in a document or enter a URL in the address of web browser, visit a digital library, then browse, search, share and in some instances download that library’s contents. Those technologies include: computers running web server software, computers running web client software (pcs, tablets, smartphones), internet protocols which control how data is transmitted and received across the internet, and internet markup languages used to design and control the functions of web pages.

Mozilla provides overview of the internet client and server communication process.

When a user enters a website into their web browser, the browser goes to a Domain Name Server (DNS) and looks for the address of the host server. The browser then sends a Hypertext Transfer Protocol (HTTP) request message to the server, asking it to send a copy of the website back to the client. This message, and all other data sent between the client and the server, is sent across the internet connection using Transmission Control Protocol and Internet Protocols (TCP/IP) which define how the data should be transmitted. If the server approves the client’s request, the server sends the client a “200 OK” message and then starts sending the website’s files to the browser as a series of small chunks called data packets. The browser assembles the small chunks or data, translates the HTML, CSS, JavaScript, PHP, and other markup language in complete website and displays it to you. (How the Web Works, n.d.)

It is the internet technology that allows you to click on the link “http://plkemp.omeka.net”

… and your web browser translates this …

into this