Disadvantages of Subdomain

1. Separate SEO Efforts: We have to develop and implement separate SEO strategies for each subdomain. 
2. Link Building: When we create a new subdomain, we have to build high-quality backlinks for that subdomain from scratch.
3. Maintenance Complexity: Managing multiple subdomains can increase the complexity of website maintenance, requiring separate hosting, SSL certificates, and server configurations for each subdomain.
4. SSL Certificate : Each subdomain often requires its SSL certificate, which can be both costly and burden to manage, especially for websites with many subdomains.
5. Cost : Hosting multiple subdomains lead to additional hosting costs, depending on the hosting provider's pricing structure.
6. Branding and Trust : Users may trust the main domain more than subdomains, potentially affecting credibility and branding efforts.
7. DNS Lookup Overhead : When a user visits a subdomain, their browser needs to perform an additional DNS lookup to resolve the subdomain to its IP address. This can add latency to the page load time, especially if the DNS resolution is slow.
8. Cookie Isolation : By default, cookies are often scoped to the full domain, including all its subdomains.

Some example of website which are running on subdomain

• English.jagran.com
• News.google.com
• Web.whatsapp.com
• Sportstar.thehindu.com
• In.bookmyshow.com
• Blog.milkbasket.com
• Timesofindia.indiatimes.com

Footer of Amazon

 Amazon has different subdomains and subpages for its products and services :-

• Music.amazon.com - Here amazon features music all over the world on subscription model. 
• Amazon Business - Here we can create our amazon business account and access the services.
• Amazon Comic Store : Here amazon created its subpage for comic book store.
• Kdp.amazon.com - Here we can Self-publish print and digital books, and reach millions of readers around the world on Amazon.
• Advertising.amazon.com - We use amazon ads to increase traffic, sales on our website.
• Amazon.com/amazonglobal - It is used to shop globally on amazon.
• Videodirect.amazon.com - Helping studios, distributors, and independent filmmakers reach audiences worldwide.
• Amazon.com/fabric/ - Amazon created a subpage for the fabric/cloth category.
• Aws.amazon.com - Here amazon provides cloud services.
• Sell.amazon.com - Here we can sell our products on amazon.

Benefits of making Subdomain for any website

 Serval benefits of making a Subdomain of a website are :-

• Organizational Structure: It can help to keep your website organized and easy to navigate.
• Targeted Audience: It can help you to target specific audiences with specific content. 
• Quick Indexing: If your main website is getting good amount of traffic and have good user experience then it will benefit your subdomain indexing.
• Improved SEO: Subdomains can potentially improve our website's search engine optimization (SEO).
• Branding: Subdomains can be used to reinforce our brand identity. For ex, we can create subdomains for specific products, services, like music.amazon.com.
• Boost Domain Authority: Subdomains are treated as separate entities to the main website, so they can positively impact the ranking of the main domain.

What is Subdomain

 It is a piece of additional information added to the beginning of a website’s domain name. It allows websites to separate and organize content for a specific function - such as a blog or an online store - from the rest of your website.