In the dns naming convention, what character(s) separate(s) a domain name from its subdomains?

In the dns naming convention, the domain name separates the sub-domains by "DOT" (.) character.

DNS or Domain Name System is written in a conventional method as Host. Domain. Root. This system allows only 255 characters while naming a domain that also includes the spaces in between. Sub-domain is the part of a large domain.

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