Exporting level and assets

When you export a level with assets,does UE4 save all assets in your asset folder or only the ones you are using in your map.thanks

Sorry for NOOB question.

Do you mean when you export it with the “export” button which you can find under the file tab? Because then it will save your whole map + meshes as a obj/fbx/… file. Otherwise you can just export your map with just moving the file from one project to another one, but then you will also have to move your assets which you have placed in your map, because otherwise you will get some reference errors