Nearly all HTML elements are either block or inline elements. The characteristics of block elements include:
1)Always begin on a new line
2)Height, line-height and top and bottom margins can be manipulated
3)Width defaults to 100% of their containing element, unless a width is specified
Examples of block elements include <div>, <p>, <h1>, <form>, <ul> and <li>. Inline elements on the other hand have the opposite characteristics:
1)Begin on the same line
2)Height, line-height and top and bottom margins can't be changed
3)Width is as long as the text/image and can't be manipulated
Examples of inline elements include <span>, <a>, <label>, <input>, <img>, <strong> and <em>.
To change an element's status you can use display: inline or display: block. But what's the point of changing an element from being block to inline, or vice-versa? Well, at first it may seem like you might hardly ever use this, but in actual fact this is a very powerful technique, which you can use any time you want to:
1)Have an inline element start on a new line
2)Have a block element start on the same line
3)Control the width of an inline element (particularly useful for navigation links
4)Manipulate the height of an inline element
5)Set a background colour as wide as the text for block elements, without having to specify a width