provided by: 
Among designers, there is an ongoing debate about which cascading style
sheets (CSS) layout works best - fixed, fluid or elastic. While some believe
that fluid is more accessible, others believe the inherent drawbacks of fluid
CSS overshadow the benefits. There remain no clear answers as to which works
best across the board, so as in most things, finding what you are most
comfortable with and listening to the feedback of your users should be the
deciding factors - when it comes to successful websites, easy usability and
equal accessibility usually rules the day. So, if you're planning a new website
or a redesign of an existing site, it's helpful to have a little background on
each of these styles to discuss with your Web designer.
Cascading style sheets are files that separate design elements into a distinct
presentation layer. Pretty simple right? It is simple, but choosing a layout -
fixed, fluid or elastic can be a challenge. Let's define each and set forth
their advantages and disadvantages.
Fixed Width Layouts
A fixed-width site is one that the width of the entire page is set with a
specific numerical value. The width is immovable and independent of the
browser's display resolution, meaning that designers have more control over how
a final page will render.
Advantages: Readable content areas are tightly controlled without having to set
minimum-maximum width and are sometimes easier to style - some designs can only
achieve their visual point from fixed width layouts.
Disadvantages: The line-width to text-size ratio doesn't increase with text
resizing which presents a problem when text size is increased by the user.
Smaller monitors force horizontal scroll bars to appear, and such layouts
prevent multiple
columns and thus content.
Fluid or Liquid Layouts
With fluid or liquid layouts, the width of the page is flexible and therefore
dependent on the width of a user's monitor. Designers do not have to specify a
wrapper width or use a percentage unit of measure. The result is that a very
efficient use of space is created and is optimal if limited room is available.
Advantages: Can work with virtually any screen view, making it a more universal
solution. Fluid layouts match a browser's default layout method and make the
most of existing screen real estate.
Disadvantages: Fluid designs provide for more white space which, if you have a
prolific writer on hand and believe in long copy pages, can result in congested
designs.
Elastic Layouts
An elastic site's elements (the main wrapper for example) are measured using ems
that are relative proportionally to the text or font size. The result is that as
text size is increases, sections measured in ems will increase in size also.
Advantages: Everything in an elastic layout resizes at the same rate. This means
that no page components will get out of proportion. Nothing looks better and is
more accessible than an elastic layout.
Disadvantages: Horizontal scroll bars could appear in an elastic layout if the
sizing is too large. Calculation can prove to be complicated and CSS does not
have the ability to have functions and conversions. Flexible images usually
require more work.
It's clear that fixed, fluid and elastic layout methods have their own unique
advantages and disadvantages. But with a little forethought, any of these
methods will work well when creating a site which meets accessibility and
usability standards. The key is determining the needs and habits of your users
and which style works best for your particular website.
Read full article at websitemagazine.com