Let's start by explaining the basics about Domains, Nameservers, Hosting services and the function performed by DNS zones and records.
A Domain is a unique name used to identify a web site on the Internet. It consists of the name, such as swmanuals and an extension .com, .org, .net, .cat, etc.
A Nameserver or DNS server is in charge of answering in which server the web or mailboxes of a specific domain are hosted.
This Nameserver response is based on a series of DNS records that allow the DNS server (Nameserver) to direct queries about the location of the web to the IP of the web server of that domain.
For example, when we indicate the name of a domain in the web browser, this makes a query to the DNS servers of the domain (Nameservers) that respond to the browser indicating the IP of the server where the web is hosted, so that the browser then makes the request for display to the server where the web of that particular domain is hosted. The same thing happens with emails, when sending an email, the DNS server will query the location of the mail server assigned to the domain to which the message is destined in order to send the email to the server assigned to the particular domain.
A Hosting is the container/hosting where a web page or a web application (files and databases) is hosted. It also hosts the emails sent to the domain and, among other things, allows you to manage the DNS Zone of the domain.
A DNS Zone is the grouping of DNS records for the same domain. This includes the records of the main domain (swmanuals.com) and the records of the subdomains of the main domain (info.swmanuals.com).
The DNS records are responsible for indicating on which server each service of a domain is located. For example, when searching for a website, it indicates which server is associated with it. Also, when an email is sent, it indicates which is the mail server assigned to the domain. Without DNS records configured in the DNS zone of the domain, it will not work.
The domains, at DNS level only have one possible configuration, change the DNS servers (Nameservers) to which they point.
In SWPanel you can do it from the domain portfolio:
In this case, the domain swmanuales.com points to the DNS servers dns3.swhosting.com and dns4.swhosting.com. (These, together with the servers dns1.swhosting.com and dns2.swhosting.com, are the servers that are assigned by default when creating a hosting service).
In this way, the DNS servers (Nameservers) dns3.swhosting.com and dns4.swhosting.com will point to the DNS Zone of the domain swmanuales.com.
Therefore, for a website to work, we need a domain configured to point to a DNS server (Nameserver) which will have a DNS zone configured with the DNS records necessary to know the location of the different servers of the domain.
As long as you have a Hosting Service or a DNS Hosting service where the DNS Zone is created, you will be able to manage the different DNS records.
In order to create a Hosting Service or a DNS Service you can follow the manual Create Hosting Service
To manage the DNS records of a DNS zone you can follow the manual Manage DNS records