If you search for "three main cumulative criteria" you find the three criteria (tldr: turnover in EEA >7.5B€ or capitalisation >75B€; 45M end users (monthly active) in EU and 10k business users (yearly active); satisfy those criteria for three consecutive years)

This only applies to companies operating in the following areas:

    online intermediation services;
    online search engines;
    online social networking services;
    video-sharing platform services;
    number-independent interpersonal communication services;
    operating systems;
    cloud computing services;
    advertising services;
    web browsers;
    virtual assistants.