A block is a rectangular region on the page into which content is assembled.

Data blocks are used to position the main page content. In most layouts the number of data blocks corresponds to the number of columns on the page.

Fixed blocks are used to place additional material at specific positions on the page. Their most common use is to create headers and footers.

The process of assembling content is the same for all blocks except for what happens when the area defined by the block is full.

  • When a data block is filled the content starts filling the next data block on the page. If there are no more data blocks, a new page is started.

  • Fixed blocks do not impose a limit on the amount of content they can contain. This means that extra content will appear below the notional bottom boundary of the block.