What is a subdomain?

A subdomain in one paragraph

A subdomain is an extra name placed in front of a domain you already own. If your domain is yourbusiness.in, then shop.yourbusiness.in, blog.yourbusiness.in and staging.yourbusiness.in are all subdomains of it. You create them yourself, they cost nothing to register, and each one can show different content or point to a different server. DNS treats names as a tree, which is why shop sits "under" your domain, as described in the original DNS standard, RFC 1034.

How a subdomain fits into a web address

Read a web address from right to left:

Part	Example	What it is
Top level domain	.in	Managed by the registry
Domain you register	yourbusiness.in	Bought and renewed through a registrar
Subdomain	shop.yourbusiness.in	Created by you in DNS, no registration needed
Path	shop.yourbusiness.in/offers/	A folder or page inside that site

A subdomain can have its own subdomain too, such as dev.shop.yourbusiness.in, but most small businesses never need more than one level. If you are new to how names and servers connect, our guide to domain vs hosting explains the basics first.

What subdomains are used for

Common, practical uses in Indian small businesses:

• A separate store or booking system. shop.yourbusiness.in points to an ecommerce platform while the main site stays on your hosting.
• A staging copy. staging.yourbusiness.in holds a test copy of the site so you can try updates before they go live.
• Regional or language sites. hi.yourbusiness.in for a Hindi version, or pune.yourbusiness.in for a branch.
• Tools and portals. portal.yourbusiness.in for a customer login, help.yourbusiness.in for a help desk service.
• Campaign pages. diwali.yourbusiness.in for a seasonal landing page you can switch off later.

Google's guidance on multi regional sites lists the trade off plainly: subdomains allow easy separation of sites and different server locations, while subdirectories are lower maintenance because everything stays on the same host.

Subdomain vs subfolder vs addon domain

These three are often confused in a control panel.

	Subdomain	Subfolder (subdirectory)	Addon domain
Example	blog.yourbusiness.in	yourbusiness.in/blog/	yourotherbrand.in
Needs registration	No	No	Yes, a separate domain
Can live on a different server	Yes	No, it is part of the main site	Yes
Typical use	A different app or platform	A section of the same site	A second, separate website

A simple rule: if the section runs on the same software as your main site, such as a WordPress blog inside a WordPress site, use a subfolder. If it runs on different software or a different server, use a subdomain. If it is a different brand, register a separate domain.

How to create a subdomain

On a hosting account with a control panel, creating a subdomain usually takes two minutes. In current versions of cPanel, subdomains are created from the Domains page:

1. Open Domains and click Create A New Domain.
2. Type the full name, for example shop.yourbusiness.in.
3. Untick Share document root if the subdomain should show different content. cPanel's documentation notes that a shared document root makes the new name serve the same content as the existing domain, and that the setting cannot be changed later.
4. Set the folder (document root) for the subdomain's files, for example shop.yourbusiness.in inside your home directory.
5. Click Submit, then upload files or install software into that folder.

Menus vary by cPanel version and by what your host enables, so your screen may look slightly different. If your domain uses your hosting's nameservers, the control panel normally creates the DNS record for you.

ODHOST note: Every ODHOST shared plan sets a subdomain allowance: Spark 5, Boost 25, Thrive 40, Turbo 80 and Elite unlimited. Each plan also has a website limit (1, 3, 5, 10 and unlimited). Whether a subdomain running its own site counts towards the website limit is not stated on the plan pages, so open a support ticket before you plan several subdomain sites on a smaller plan. Compare the plans on the shared hosting page.

DNS records for a subdomain

If your DNS is managed somewhere else, such as at your registrar or a DNS service, you add the subdomain record yourself:

• Use an A record when the subdomain points to a server's IP address, for example your hosting server.
• Use a CNAME record when the subdomain should follow another hostname, such as a store or help desk platform that gives you a target like stores.example-platform.com.

; Subdomain on your own hosting server
shop    IN  A      203.0.113.10

; Subdomain handed to an outside service
help    IN  CNAME  yourbusiness.helpdesk.example.

Our help article on A record vs CNAME explains which to choose and why a CNAME cannot sit on the root domain. New records can take some time to be seen everywhere; see DNS propagation if the subdomain does not load straight away.

SSL certificates for subdomains

A certificate only protects the exact names it lists. A certificate for yourbusiness.in and www.yourbusiness.in does not automatically cover shop.yourbusiness.in. There are three ways to cover a subdomain:

1. Add it to the certificate. Many hosts issue or reissue certificates for each domain and subdomain on the account once DNS points to the server.
2. Use a wildcard certificate. A certificate for *.yourbusiness.in covers every first level subdomain, but not dev.shop.yourbusiness.in.
3. Let the outside platform issue it. If the subdomain points to a third party service by CNAME, that service normally provides the certificate.

After creating the subdomain, check the certificate status in your control panel, then visit the subdomain with https://. Our guide on how SSL certificates work covers certificate types in more detail.

Email and subdomains

Email records are not inherited from the main domain. SPF is checked for the exact domain a message claims to come from (RFC 7208), so if a tool sends mail as alerts@billing.yourbusiness.in, that subdomain needs its own SPF record, and its own DKIM key if the sending service provides one. Many businesses use a subdomain such as mail.yourbusiness.in or news.yourbusiness.in for bulk newsletters, which keeps that traffic separate from day to day office mail.

The guide to SPF, DKIM and DMARC shows the record formats, including the DMARC sp= tag that sets a policy for subdomains.

Developer notes: cookies, CORS and installs

• Cookies. MDN explains that a cookie set with a Domain attribute of yourbusiness.in is sent to all its subdomains, while a cookie without it stays on the exact host that set it. Keep login cookies host only unless you deliberately want single sign on across subdomains.
• Cross origin requests. shop.yourbusiness.in and yourbusiness.in are different origins to a browser, so API calls between them need the right CORS headers.
• WordPress on a subdomain. Install it into the subdomain's own document root, with its own database, and set the site URL to the full https:// subdomain address. Our guide to installing WordPress in cPanel works the same way for a subdomain.
• Staging subdomains. Protect them with a password or a noindex setting so search engines do not index a duplicate of your live site.

A quick checklist before you add a subdomain

1. Decide whether a subfolder would do the job more simply.
2. Check your plan's subdomain and website limits.
3. Create the subdomain and point its DNS record to the right server.
4. Confirm SSL covers the new name before you share the link.
5. Add SPF and DKIM records if anything will send email from it.
6. Block search indexing on staging or test subdomains.