Domain name / domain
Domain name is the so-called postal code required for indexing your web hosting (files/emails/databases).
More information about this can be found in the Wikipedia article.
Radicenter is only domain reseller for various central registries (Estonian Internet Foundation for .ee domains, EURid for .eu domains, etc.).
Domain prices are set by central registries.
Web hosting is the so-called storage for your files/emails/databases. Web hosting service is provided by Radicenter.
If the domain expires/stops or is deleted/quarantined – then it is still possible to access the files via the server IP address.
If the prepayment of the web hosting account ends, the domain will remain valid but after a certain time the web hosting account will be deleted and will stop working (along with the data and the website/e-mail/databases that were associated with that account).