Sun lounger
Looseley speaking, sun loungers are a form of bed, except that rather than being used for sleeping they are used for relaxing in the sun on a bright warm day.
The sun lounger comes in many different forms from the very basic to the luxurious and from the fold-away version to the hardwood heavily cushioned version.
Cheap and cheerful
The most basic of sun loungers will typically have a metal frame across which is stretched a durable fabric. These loungers will fold flat for storage. This works by having two leg rests that fold inwards against the fabric surface, and a leg and upper body section that also fold flat. This makes these lounger beds very easy to put into storage over winter.
From an appearance perspective they normally come with brightly coloured fabrics which can be replaced or interchanged. The comfort of the lounger is based upon the flexing of the stretched fabric around the frame. Most need to be taken indoors when it rains.
Better quality sun loungers
Moving away from the most basic of sun loungers there is a broad selection of more up market, comfortable and visually appealing beds from which to choose. Some of these loungers will fold for storage whilst others will not.
Many of the better lounger beds are made of hard wood and they come with a thin mattress for extra comfort. This mattress sits on top of a wooden slatted top surface (much like a pine bed) and the mattress section may be in two or more sections to facilitate flexibility and bending. If the lounger is to be left outside, then the padded mattress section needs to be removed overnight or if rain is expected.
Adjustment
All but the most basic of sun loungers are adjustable for backrest and leg rest inclination so that it is possible to relax in anything from a very prone to a nearly seated sunbathing position.
The adjustment may be by means of a ratchet mechanism (e.g. metals framed loungers) to slots in groves (e.g. most of the hardwood framed loungers). In all cases it is possible to produce many different postures by varying the angles of the back and leg rest sections of the lounger.
Appearance
The most attractive loungers are often those with the wooden frames and mattress like cushioning. However, there are a number of very aesthetically desirable sun loungers that are made to the contours of the body and they often have free flowing shapes that are curved and pleasing to look at. Most loungers of this type are moulded using a plastic or polyurethane like material and they are hardwearing and capable of being left out in the elements.
Sun loungers at the budget end of the market will not have arm rests, however many of the more expensive models will have arm supports and they may be supported on three or more legs sections (pairs of legs).
For an artificial sun tan please see this page sunbeds about tanning beds used to get a "fake" sun tan.