The border shorthand property sets all the border properties in one declaration.

The properties that can be set, are (in order): border-width, border-style, and border-color.

It does not matter if one of the values above are missing, e.g. border:solid #ff0000; is allowed.

border-width: Specifies the width of the border;

border-style: Specifies the style of the border;

border-color: Specifies the color of the border;