Application.loadlevel & Object.dontdestroyonload

"application.loadlevel"

　　

Only the buttons set in the File->build setting can be loaded.

When level loading is complete, monobehaviour. onlevelwasloaded is called on all active game objects.

When loading a new level all game objects that has been loaded before is destroyed. If you want to let an object survive when loading a new level, use object. dontdestroyonload.

Calling Loadlevel would update Application.loadedlevel and Application.loadedlevelname.

Reference: file://localhost/Applications/Unity/Unity.app/Contents/Documentation/Documentation/ScriptReference/ Application.LoadLevel.html

"Object. Dontdestroyonload"

When loading a new level all objects in the scene is destroyed, then the objects in the new level is loaded. In order to preserve a object during level loading call dontdestroyonload on it. If The object is a component or game object then its entire transform hierarchy would not be destroyed either.

Reference: file://localhost/Applications/Unity/Unity.app/Contents/Documentation/Documentation/ScriptReference/ Object.DontDestroyOnLoad.html