How do I make a program that understands what the given data means?
Understanding, that’s the proverbial $64,000 Question. I reckon it’s all in your definition.
Fortunately, you narrow down the definition of what you mean in the Question details, which are something like Metadata, or data about data; in other words, the metadatastands under the data…. ;^)
WordNet is a lexical database for the English language. It groups English words into sets of synonyms called synsets, provides short definitions and usage examples, and records a number of relations among these synonym sets or their members. WordNet can thus be seen as a combination of dictionary and thesaurus. While it is accessible to human users via a web browser, its primary use is in automatic text analysis and artificial intelligence applications.
DBpedia (from “DB” for “database”) is a project aiming to extract structured content from the information created as part of the Wikipedia project. This structured information is then made available on the World Wide Web. DBpedia allows users to semantically query relationships and properties associated with Wikipedia resources, including links to other related datasets. DBpedia has been described by Tim Berners-Lee as one of the more famous parts of the decentralized Linked Data effort.