What is a Subdomain?

Subdomains play an important role in the field of web hosting and websites, as they allow for a hierarchical subdivision of a domain. But what does this mean exactly and what are subdomains used for? This and more information on the topic is explained in the following article.

When it comes to the topics of websites and web hosting, the term subdomain eventually comes up. To understand what exactly a subdomain is, the general structure of a domain (commonly referred to as an internet address) must first be considered. Essentially, a domain consists of three individual parts, each separated by a dot. The three parts of a domain are:

• Subdomain
• Domain Name
• Top-Level Domain (TLD)

Here is an example for illustration:

www.hosttest.de

• www corresponds to the subdomain
• hosttest corresponds to the domain name
• de corresponds to the top-level domain (TLD)

So, a subdomain is the front part of a domain that precedes the domain name and the top-level domain (TLD). In the hierarchical structure, the subdomain is subordinate to the main domain. The name can be chosen arbitrarily. All letters from A to Z, including all umlauts, as well as the numbers from 0 to 9 and the hyphen are allowed. A subdomain can have a maximum of 63 characters. Further information on this can also be found in the article What is a Domain?.

Why are Subdomains Used?

The use of subdomains in web hosting can have various reasons. Usually, it is about separating specific areas of a website from other parts of the web project. This allows for a clean technical and organisational separation of different content without the need to move them to separate domains. This way, the fundamental connection to the domain name remains, which sends important signals to both website visitors and search engines like Google.

Subdomains are used to create a unique and logical technical structure for web presences. They enable the creation of unique and easy-to-remember addresses on the internet. Examples of applications can include:

Separation of technical services of a website

Most commonly, subdomains are used for offering various technical services of a web project. Various web services such as email servers or FTP servers generally require their own subdomain through which they can be uniquely identified on the internet. Especially for large websites, separation for structural and organisational reasons makes sense:

• www.domainname.tld
• The www subdomain is a standard subdomain under which the contents of a website are typically accessible.
• ftp.domainname.tld
• The ftp subdomain is for the File Transfer Protocol, which allows data exchange between a local computer and the server on the internet.
• imap.domainname.tld
• The imap subdomain hosts the server for email reception via the IMAP protocol.
• smtp.domainname.tld
• The smtp subdomain hosts the server for email sending via the SMTP protocol.
• shop.domainname.tld
• The shop subdomain can be used to make an online shop accessible on a website.
• forum.domainname.tld
• The forum subdomain can be used to make a forum accessible on a website.

Multilingual websites

For extensive online projects available in multiple languages, the linguistically different content is moved to their respective subdomains. For example, de.domainname.tld can be used for German content and en.domainname.tld for English content.

Online projects with local relevance

Even for large web projects with a local focus, using subdomains can make sense to better target different regions. For example, a real estate portal could offer its properties optimised for the Berlin region under the subdomain berlin.domainname.de and optimised for the Cologne region under köln.domainname.de.

How to set up subdomains?

The technical setup of subdomains is usually done through the web hosting Control Panel. This is the management interface provided to each customer by the web hosting provider. In addition to all the important settings and control over the functions of your own web hosting, the owner of a domain can create and manage the individually required subdomains here. Restrictions may only exist based on the web hosting package used.

If you have chosen suitable web hosting on a powerful server or affordable web space and the corresponding domain, then you too can benefit from the advantages of individually created subdomains for your own online project.
 

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