Focal Length Examples

18mm -  This photograph was taken with an 18mm lens, we can see that more of the background and foreground can be seen in the shot. 

35mm - This photograph was taken with a 35mm lens, we can see that the computer screen in the bottom right cannot be seen anymore and the background and foreground are slightly blurred.

55mm - This photograph was taken with a 55mm lens, we can see that most of the window can't be seen and that the background and foreground are even more blurred.

We can see from these examples that the higher the setting of the focal length of the lens the more slightly blurred the picture is and the less "wide-angle" look you will get from the lens.