Subdomain

A subdomain is the part that comes before the main domain (like blog in blog.example.com), letting a business separate several sections under one main name.

A subdomain is an organizing tool: a blog, shop, user panel and payment gateway can each sit on a subdomain to be managed independently. But that same separation has a cost for analytics. Browsers see subdomains as partly separate for cookies and storage, so without correct setup, a user moving from one subdomain to another may be counted twice and their session broken. The choice between a subdomain and a path (blog.example.com versus example.com/blog) is not just technical taste; it directly affects data unity and tracking a user across sections. The practical rule is that if you want to see the user's journey across sections as one, either use a path instead of a subdomain or set up cross-domain tracking correctly.