CSS Styles
The border-style property sets the style of an element's border. This property can have from one to four values (for every side of the element one value.)
border solid
border-style: solid;
This is a div tag with border style solid
border dotted
border-style: dotted;
This is a div tag with border style dotted
border dashed
border-style: dashed;
This is a div tag with border style dashed
border double
border-style: double;
This is a div tag with border style double
border groove
border-style: groove;
This is a div tag with border style groove
border ridge
border-style: ridge;
This is a div tag with border style ridge
border inset
border-style: inset;
This is a div tag with border style inset
border outset
border-style: outset;
This is a div tag with border style outset
border-style can also have the values none and hidden. They have the same effect, except hidden works for border conflict resolution for <table> elements. In a <table> with multiple borders, none has the lowest priority (meaning in a conflict, the border would show), and hidden has the highest priority (meaning in a conflict, the border would not show).