I find this infographic helpful. If you’re interested, it’s easiest to read as a PDF
The best source I know of for the EU view on this stuff is here: https://ec.europa.eu/info/law/law-topic/data-protection/eu-data-protection-rules_en
Here’s the Brit version:
https://ico.org.uk/for-organisations/guide-to-data-protection/guide-to-the-general-data-protection-regulation-gdpr/
Here’s what being sold for WP sites:
https://www.tutorialchip.com/wordpress/best-wordpress-plugins-for-gdpr-compliance-2021/