Your syntax is full of errors.
It has to be
London
and yes, in short this is identical to
London
There is also three other short forms:
padding: 10px 5px;
means to apply 10px top/bottom, and 5px left/right.
padding: 10px 5px 0;
means to apply 10px top, 0 to bottom, and 5px left/right.
padding: 1px 2px 3px 4px;
means to apply 1px top, 2px right, 3px bottom, 4px left (clockwise, starting at top).
not valid
London
use
h2{
background: #ccc;
}
London
Fiddle