Mattress shopping is just one of those things that always seems to take longer than it's slated for. The huge range of variation is part of the problem; however, you can cut down the time you spend considerably by knowing the fundamental principles of what makes a good mattress before you start shopping around.
Of course, all of the attributes of a good mattress should be to support the quality of your sleep - otherwise, why aren’t we still snoozing on a bed of leaves like our distant forebears did? This drive to greater comfort is what first spawned the coiled steel spring, straw-filled and batting-topped first modern mattresses made presumably in Germany. These have progressed to variants filled with water, air, and even the advanced mattresses comprised of viscoelastic polyurethane foam.
As the online space has exploded with on-demand consumer goods, many people just like you now prefer to buy a mattress online, and have to depend on reviews and the stated qualities before purchase. Therefore, it boils down to understanding the differences in the mattresses you’re considering.
The polyurethane we mentioned earlier; memory foam is marketed as such because of its ability to minimize pressure on your joints. You’ll notice that you tend to sink into this kind of mattress, thereby creating slightly more heat than you would on a firmer surface. It’s a good thing you can check the poundage per square feet of pressure to find out the degree of “give” before you buy.
These types of mattresses are valued for their ability to change pressure to suit the consumer. Of course, the entire mattress isn’t filled with air; just the topmost layer. The rest is some type of approved foam. Keep in mind that there could be some noise since there’s air inside, as well as reported instances of mechanical failure - but these are not widespread. The best ones allow you to vary the pressure of one half of the mattress independently of the other half.
This is a sleeping surface of the classic variety. You almost certainly slept on one as a child, and perhaps still do - the metallic coils are close to the top of the surface, and are marketed by gauge (thickness, for the most part). The gauge helps you determine if it can support your weight, and how firm the bed will be when you lay on it.
Latex is a type of rubber that comes from certain trees, and possess qualities that are usually in diametric opposition - which makes them difficult to obtain with a single material. These qualities are softness and springiness. They tend to cost more than other types of mattresses because of these properties, and can come in material blends that have other advantages.
There are hybrid mattresses of several variants; it’s best to understand the properties of each before you buy. The ultimate point of a good mattress is the extent to which it facilitates sleep and acts as the solution to wakeful nights. Happy shopping!