gl.ARRAY_BUFFER stores vertex data like coordinates and colors, while gl.ELEMENT_ARRAY_BUFFER stores indices that reference the vertices in an ARRAY_BUFFER. The key difference is that gl.ARRAY_BUFFER binding is a global state, but gl.ELEMENT_ARRAY_BUFFER binding is part of a Vertex Array Object's (VAO) state.
Feature
  
gl.ARRAY_BUFFER
  
gl.ELEMENT_ARRAY_BUFFER
Purpose
  
Stores vertex attributes like positions, colors, and texture coordinates.
  
Stores indices for drawing elements.
Usage
  
Used with functions like gl.drawArrays() to draw vertices in the order they appear in the buffer.
  
Used with functions like gl.drawElements() to draw vertices in a specific order dictated by the indices in the buffer.
Binding
  
A global state. The buffer is associated with a specific vertex attribute when gl.vertexAttribPointer() is called.
  
A state of the currently bound Vertex Array Object (VAO).
Data
  
Contains the actual vertex data, such as vec3 or vec4 data.
  
Contains unsigned integer data, such as Uint16 or Uint32, that points to vertices in the gl.ARRAY_BUFFER.