title: Differences between ng build and ng build --watch
body: <p>I have updated my Angular application to Angular 8 and now I want to try "Differential Loading". In the <code>tsconfig.json</code> the <code>target</code> is set to <code>es2015</code>.</p>
  
  <p>Now if I build the application using <code>ng build</code>, I get the following output from Angular-CLI:</p>
  
  <pre><code>Date: 2019-07-02T15:50:56.861Z
  Hash: 33c0be7176e97a0b4271
  Time: 35935ms
  chunk {main} main-es5.js, main-es5.js.map (main) 3.3 MB [initial] [rendered]
  chunk {polyfills} polyfills-es5.js, polyfills-es5.js.map (polyfills) 762 kB [initial] [rendered]
  chunk {runtime} runtime-es5.js, runtime-es5.js.map (runtime) 6.08 kB [entry] [rendered]
  chunk {scripts} scripts.js, scripts.js.map (scripts) 104 kB [entry] [rendered]
  chunk {styles} styles-es5.js, styles-es5.js.map (styles) 30.5 kB [initial] [rendered]
  chunk {vendor} vendor-es5.js, vendor-es5.js.map (vendor) 4.84 MB [initial] [rendered]
  
  Date: 2019-07-02T15:51:25.559Z
  Hash: dbbb4a6cfe77900eb200
  Time: 28589ms
  chunk {main} main-es2015.js, main-es2015.js.map (main) 2.92 MB [initial] [rendered]
  chunk {polyfills} polyfills-es2015.js, polyfills-es2015.js.map (polyfills) 378 kB [initial] [rendered]
  chunk {runtime} runtime-es2015.js, runtime-es2015.js.map (runtime) 6.08 kB [entry] [rendered]
  chunk {scripts} scripts.js, scripts.js.map (scripts) 104 kB [entry] [rendered]
  chunk {styles} styles-es2015.js, styles-es2015.js.map (styles) 30.5 kB [initial] [rendered]
  chunk {vendor} vendor-es2015.js, vendor-es2015.js.map (vendor) 4.74 MB [initial] [rendered]
  </code></pre>
  
  <p>If I build the application using <code>ng build --watch</code> (same bundles as <code>ng serve</code>), I get this output:</p>
  
  <pre><code>Date: 2019-07-02T15:55:06.631Z
  Hash: 123299dcdc0cbcb1c386
  Time: 36614ms
  chunk {main} main.js, main.js.map (main) 2.92 MB [initial] [rendered]
  chunk {polyfills} polyfills.js, polyfills.js.map (polyfills) 375 kB [initial] [rendered]
  chunk {polyfills-es5} polyfills-es5.js, polyfills-es5.js.map (polyfills-es5) 503 kB [initial] [rendered]
  chunk {runtime} runtime.js, runtime.js.map (runtime) 6.08 kB [entry] [rendered]
  chunk {scripts} scripts.js, scripts.js.map (scripts) 104 kB [entry] [rendered]
  chunk {styles} styles.js, styles.js.map (styles) 30.5 kB [initial] [rendered]
  chunk {vendor} vendor.js, vendor.js.map (vendor) 4.74 MB [initial] [rendered]
  </code></pre>
  
  <p>Why aren't the same bundles generated? I ask this because I don't know what the correct way is to embed those script to the <code>html</code>-files.</p>