The element generates a block element box, generating line breaks both before and after the element when in the normal flow.
The element generates one or more inline element boxes that do not generate line breaks before or after themselves. In normal flow, the next element will be on the same line if there is space
Note: Browsers that support the two value syntax, on finding the outer value only, such as when
display: block or
display: inline is specified, will set the inner value to
flow. This will result in expected behavior; for example if you specify an element to be block, you would expect that the children of that element would participate in block and inline normal flow layout.