Understanding the Difference Between a DNS Name and a Hostname

Networks and the Internet rely on various naming and addressing systems to facilitate communication. Two of the most crucial components are hostnames and DNS names. In this article, we will delve into what each of these terms means, their differences, and how they are used in both local networks and the global internet.

What is a Hostname?

A hostname is a label assigned to a device on a network. It is commonly used to identify the device in a human-readable format. For example, you might assign a hostname such as printer1.local. Hostnames are used primarily within local networks, making them easy to manage and understand within a small environment.

What is a DNS Name?

A DNS name, on the other hand, is a Domain Name System (DNS) name that refers to a hierarchical naming system used to translate human-friendly domain names into IP addresses. An example of a DNS name is , which is used to locate the server associated with that domain on the internet.

Key Differences

Scope of Use

Hostnames are typically used within local networks, whereas DNS names are used in the global internet context. This is because DNS names allow for resolution of hostnames to IP addresses, which is necessary for communication over the internet.

Structure

Hostnames can be a single label or part of a fully qualified domain name (FQDN), while DNS names usually refer to the full FQDN. For example, in the DNS name , www is the hostname, and is the domain name.

Function

Hostnames primarily identify a device on a network, whereas DNS names resolve to an IP address, enabling communication over the internet.

Examples

Consider the DNS name In this instance, www is the hostname and is the domain name. The complete DNS name is used to resolve the IP address of the web server hosting the site.

In a local network context, a device might have a hostname like printer1.local. This device will typically have at least one IP address and, if it has a static IP address, it will also have gateway router, network mask, and name server information hard-coded. These details are essential for the device to communicate within the network and on the internet (if applicable).

A DNS domain name system (DNS name) is a fully qualified domain name (FQDN) that uniquely identifies a resource on the internet. It consists of multiple labels separated by dots, forming a hierarchical structure, such as

Hostnames are often only locally known entities. A host can have a hostname that is just about anything, provided it is unique within its local network. A device will create a hostname if not already provided.

If the IP address of a device is assigned via DHCP, all of the parameters required for communication (including the hostname) are automatically assigned by the DHCP server. DHCP can also be configured to assign a bulk hostname if one is not hard-coded.

DNS and DHCP are often used together, with DHCP dynamically assigning hostnames to devices and DNS resolving those hostnames to IP addresses.

Even though DNS names can include hostnames, not all hostnames are DNS names, particularly in the context of local networks.

Conclusion

Understanding the difference between a hostname and a DNS name is crucial for effective network management and internet communication. While hostnames are primarily used within local networks for ease of identification, DNS names are essential for resolving hostnames to IP addresses, enabling global communication over the Internet.

Keywords: DNS name, hostname, domain name system