App Building & Devbeginner
Localhost
Definition
A way to run your app on your own computer for development and testing, it's only accessible from your machine. Usually accessed at http://localhost:3000 or similar.
Why it matters
Localhost is where all development happens before code goes live. Understanding it means you can follow developer tutorials, test changes, and review work before it's public.
Example
A founder runs npm run dev and opens localhost:3000 in her browser to see her app exactly as it will appear live, without publishing anything publicly.
Related terms
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