Metadata

Metadata plays a crucial role in various areas and applications:

• Search and discoverability: They make it easier to search for specific data and find it quickly by allowing it to be filtered or sorted according to specific criteria.
• Organization and management: Metadata helps to categorize and organize information, which is especially important in large databases or archives.
• Context and understanding: It provides important context to data, enabling its interpretation and correct use.
• Interoperability: In an interconnected world, standardized metadata enables different systems to share and use information effectively.
• Preservation and long-term archiving: Metadata is crucial for the preservation of digital data by providing information about its origin, changes and necessary conditions for access and use.

The diversity of information types, application areas and different systems presents a challenge that can be met by using metadata. Metadata not only enables the structural description of resources to improve their findability, but can also initiate processes to implement specific programming instructions. In addition, they have the ability to evaluate, define and structure content as well as to show links between different resources. In their role as meta-metadata, they provide essential information about data models, syntax and semantics that are necessary for defining languages and enabling computational linguistic applications.

The uniform labelling of certain resources and information types with metadata according to a standardized scheme allows them to be used by various systems and programs. This can be seen, for example, in the interaction between users (via browsers) and websites (servers), when websites are searched by search engines and their crawlers, in the migration of servers and databases and in communication between mobile devices and NFC terminals.

Here are some examples to illustrate the diversity and importance of metadata in different contexts:

• Books: For books, metadata often includes the author's name, publisher's name, ISBN number, year of publication, edition and similar information.
• Music files: For music recordings, typical metadata includes details such as the artist name, artist name, song title, music genre, composer, label, year of release and more.
• Images and videos: Metadata for images and videos can include the location and date of capture, camera type, aperture values, lens, focal length, color space, exposure time, and for videos additionally the audio and video codec, duration of playback, bit rate, language and more.
• Files: For digital files, the metadata ranges from the file name, file size, creation and modification date, file type, storage location to information about the owner and file permissions.
• Documents (PDF, Word, etc.): Information about the author, when the document was created and last edited, how many pages it consists of and in which language it was written.
• Websites (HTML pages): For HTML pages, typical metadata includes the page title, page description, keywords, character encoding, author, copyright, instructions for web crawlers and more.

These examples highlight how metadata is used in different areas to capture essential information that is essential for organizing, searching and processing data.

Metadata is essential in HTML programming in order to provide servers, browsers and search engine bots and crawlers with relevant information. This data can control the behaviour of a website, for example by triggering automatic redirection or optimizing the display on mobile devices. Metadata is mainly placed in the head section of an HTML document, but can also be generated automatically for several documents at the same time. They are structured as meta tags that consist of specific attribute-value pairs and are inserted into the head element of the document.

These meta tags can contain a variety of information, including meta descriptions, website titles and keywords as well as author details. In the context of search engine optimization (SEO), meta tags are particularly important for giving instructions to search engine bots, which is made possible by the "robots" tag. Metadata also contains information on languages and content types, with the MIME data standard playing a key role. It ensures that browsers can interpret and display the content correctly. Metadata therefore makes a significant contribution to the functionality, accessibility and findability of web content.

Correctly implemented metadata helps search engines to recognize the relevance of a website for certain search queries. This leads to a better ranking in the search results and increases the likelihood that users will click on the website. Although the direct ranking of the page depends more on other factors (such as content and backlinks), an appealing title and a compelling description can improve visibility and CTR.

Metadata plays a central role in SEO as it provides search engines with important information about the content of a web page. The meta title and meta description in particular are crucial for the presentation of a page in the search results. The meta title serves as the title of the page and should both contain relevant keywords and appeal to the user in order to increase the click-through rate. The meta description provides a brief summary of the page content and also serves to arouse the interest of potential visitors. Although this metadata does not directly influence the ranking of a website, it can significantly increase the visibility and attractiveness of the page in search results. By carefully selecting words and phrases in this metadata, website operators can emphasize the relevance of their site for certain search queries and thus drive more qualified traffic to their site.