docs: improve wording clarity in UI introduction

Author: Nikhil166-tech

src/content/learn/describing-the-ui.md

@@ -4,7 +4,7 @@ title: Describing the UI
 
 <Intro>
 
-React is a JavaScript library for rendering user interfaces (UI). UI is built from small units like buttons, text, and images. React lets you combine them into reusable, nestable *components.* From web sites to phone apps, everything on the screen can be broken down into components. In this chapter, you'll learn to create, customize, and conditionally display React components.
+React is a JavaScript library for rendering user interfaces (UI). User interfaces are built from small units like buttons, text, and images. React lets you combine them into reusable, nestable *components.* From websites to phone apps, everything on the screen can be broken down into components. In this chapter, you'll learn how to create, customize, and conditionally display React components.
 
 </Intro>