The company you pay each year to hold your domain name, such as GoDaddy or Namecheap.
Like the land titles office for your web address: it records that the name is yours.
Domain Security covers registration and DNS, so the renewal date does not slip and the registrar login is protected.
How do I find my registrar? Look up your domain in a WHOIS tool or check old invoices. Then confirm the account is in your name.
Every WILDCARD card exists to solve one named problem. Find yours.