why is my react hook running code example

Example 1: react useEffect

import React, { useEffect } from 'react';

export const App: React.FC = () => {
  
  useEffect(() => {
        
  }, [/*Here can enter some value to call again the content inside useEffect*/])
  
  return (
    <div>Use Effect!</div>
  );
}

Example 2: how to use hooks react

const App = () => {
const [students , setStudents] = useState([]);
  
  return (
// put in the jsx code here
  )
}