EUR-Lex - Access to European Union law, as its header reads - is managed by the Publications Office of the European Union. It is where the Official Journal of the European Union appears, and it gathers around the journal what is needed to read an act in context: its history, its amendments, the rulings on it and the national laws that carry it out.
The home page shows the structure. EU law covers treaties, legal acts, consolidated texts, international agreements, preparatory documents, EFTA documents, lawmaking procedures and summaries of EU legislation. EU case-law covers case-law, reports of cases and the directory of case-law. National law and case-law covers national transposition, national case-law and JURE case-law. Every document belongs to a CELEX sector, which is why the CELEX number works as a key across all of them.
Documents are published in the EU languages, and a document page lists which language versions exist and can show up to three side by side. Pages run long: the Document information tab of the General Data Protection Regulation alone lists a long run of judgments under Affected by case, each tied to the article it interprets. That depth makes EUR-Lex slow to copy by hand and useful as structured data.