Q:

Meaning of src, public, and build folders

I have recently started with programming, and I've just purchased a reactJs template, and the content comes ordered within folders named src, public and build; can you explain to me the reason of those folders? How does a web app work with those folders?
I ask this because I believe those names for folders are a de facto standard in web app coding.

A:

Here's a simplistic rundown:
public means the web accessible root of the site. Basically whatever is in that folder can be opened from  browser address bar. Server won't provide user access to files outside public
build is where compiled version  of assets are placed when you run npm build. This is what will get delivered to user
src (short for "source") contains your working files that will be used later to create the build 

