What is a fixed width theme?
A fixed width theme always stays the same size as its original design width. For example most fixed width themes are set to 800 pixels wide to fit a monitor resolution of 800×600. If the person viewing your website has their monitor resolution set to something higher than 800×600 open space will show up on both sides of the theme keeping the theme directly in the middle or sometimes on the left or right leaving open space on either of those sides.