More advanced than AdSense.
Often accessed through partners.
Suited for larger or growing publishers.
Works best with strong compliance.
Google AdX is usually seen as a more advanced advertising option than AdSense. It can provide stronger competition for inventory and more optimization control.
Most smaller publishers do not access AdX directly at the beginning. Many use monetization partners that help manage the setup.
AdX starts to make more sense once a website already has quality traffic, good viewability, and a serious publishing strategy.
For beginners, AdX is often better seen as a future step rather than the first monetization tool.