The property margin specifies the spacing between elements HMTL.
It has no color, is always transparent.
You can specify a different gap on each side
You can also set all on the same line (top, right, bottom, left)
If top and bottom margins are equal (10px), and left and right margins are equal (7px), we can specify only 2 values:
If you specify only one value, the four sides have the same value.