Preloaded Assets in Unity,By Using This You Can Reduce Your Scene Loading Time

Preloading Of Assets Can done  Using Player Setting.............
 Go to the File >Build Settings (Or you can Directly Open Build Settings By Using Cntrl+Shift+B)

Then Click On The Player Settings Button In build Settings.
After that You Will See Player Settings on right Side  As Shown In Image
In Player Settings You Can see Other Settings and In Other Settings there are One Option Preloaded Assets in This Option Place Your objects and texture you can Also Place Shader In Preloaded Assets.

By doing this Your Scene Loading Time Will reduce You can Place As Many Objects As you Want But Sometimes More Preload Assets Cause a Crash in Devices So please Check Your Scene After Preloading ,

As You Can see i placed Two assets and One texture in Preloaded Assets