@ Priyanka, there's no display: outline'. I guess you mean 'inline'.
'display: block' displays an element as block element. And 'display: inline' displays an element as an inline element.
You must post your code here so we can see what went wrong.
when you displays an element in block form all of its contents breaks to display in block format and extends downward as much as it can take while "inline value" do otherwise by making all block contents display in a straight line far as much as it can take