What thing is making Scene view and Game view appear different? (See details)

With Unity 5.3.4 I had installed the optional Standard Assets Example Project. I’m a beginner in game development and programming. The Scene view and Game view shown in the project ‘Standard Assets Example Project’ is–

When after playing around for some time I tried to create a new project ‘Roll a Ball’ inspired from the tutorials provided on the website, the Scene view and Game view looked like this–

What am I missing? And is that asset or that component very much important? Did I change any default setting or something inadvertently that you can point out? Thanks in advance!

Looks like you removed the skybox somehow. You can restore it from the Window->Lighting menu option.