What is a sub-domain?

Just by looking at it as ‘word’ or ‘short-expression’ it is obvious that a ‘Sub-Domain‘ is part of  a ‘Primary Domain‘ (also known as: main / TLD* Domain, it belongs to it because it has been created by adding a word or a number to the main initial Domain. In the Domain Name System hierarchy a ‘Subdomain’ is a domain that is a part of another domain. A ‘Sub-Domain can be also seen as a subdivision of a Domain.

For example, if a domain offered an online store as part of their website, example: [worldsbikestore.com],

it might use the subdomain: [shop.worldsbikestore.com]

Unlimited ‘Sub-Domains’ can be created of a main TLD Domain*

*Shared web hosting usually limits the number of Sub-Domains that a User can create into a single web-hosting account.

TLD – stands for: Top Level Domains.