| A | B |
|---|
| Collapse | What happens in the box model when adjacent top and bottom margins combine into a single margin equal to the greater of the two values |
| Page Flow | The default order of a Web page in which elements are displayed based on the sequence in which they appear in the HTML code |
| Relative Positioning | A positioning technique that lets you make adjustments to the default position of an element while preserving the space allotted to the element in the default page flow |
| Absolute Positioning | A positioning technique that takes an element out of the page flow entirely and allows other elements to flow into the space it would have occupied |
| Stack | To overlap Web page elements using positioning |
| Layer | A new level displayed on top of the basic flow of elements on the Web page, into which a positioned element is placed |
| Fixed Positioning | A positioning technique similar to absolute positioning that places an element at the top of the stacking order and positions it relative to the browser window rather than to a Web page element |
| Fixed Layout | A Web page layout that uses a fixed page width |
| Fluid Layout | A Web page layout that gives a Web page the flexibility to adjust its width based on the width of a user's browser window |
