Css Positioning
1.position：
| static |
The default value is not located |
| fixex |
Fixed position, when there is a scroll bar with the scroll object does not |
| relative |
Relative positioning of the elements will move in accordance with the original position of the element |
| abosolute |
After the absolute positioning, the position is set to absolute, the element is arranged to be defined within the specified containing element Coordinates (x coordinate, y coordinate}, absolute positioning element relative nearest positioned parent element, if the element is not set Bits parent element, its position relative to the <html>. |
Specific usage: position: xx
2.z-index：
A large number of rules to follow that is closer to the user, the code shown below position1 and position2 represent different blocks of two colors, because position1 is written z-index: 2, therefore this box where the user position1 closer that covers the other block, above.
