How many subdomains can be used for a website or blog?

The number of subdomains you can create for a website or blog is essentially unlimited from a technical standpoint. There are no universal restrictions on how many subdomain levels you can have pointing to different sections or content within your main domain.

However, from an organizational and SEO best practices perspective, it's generally recommended to use subdomains thoughtfully and in moderation. A few key points on subdomain usage include:

First, each subdomain you create should serve a very distinct, logical purpose for separating out certain content (e.g. blog.example.com, shop.example.com).

Second, avoid creating unnecessary subdomains, as too many can dilute your ability to build focused SEO authority. It's better to limit yourself to just a handful of key, purposeful subdomains.

Third, make sure to choose descriptive subdomain names, configure them properly for search engines, and implement analytics tracking to measure their performance.

Many websites actually get by just fine with zero subdomains at all, or maybe just one for a blog (www.example.com/blog). But larger, more complex sites may benefit from utilizing a few strategic, well-structured subdomains.

The number you ultimately create should align with your specific goals and content architecture. However, going overboard with an excessive number of subdomains can create more potential headaches than benefits from a usability and SEO perspective.