Wire braided hoses get their strength from having a braided piece of wire within the hose.  Usually they are made with a tube surrounded by a wire braid which is in turn surrounded by an outer tube.  

Higher strength hoses require a double wire braid

Some better quality hoses have an outside cover overall.  Outside covers can be provided for high wear, chemical resistance and non-marking. A car wash generally would want to have high wear because their hoses are being dragged around a lot.  Working with harsh chemicals needs to have a cover which resists the chemical being used.  When working in sensitive areas such as wood decks, tile and brick patios it is wise to use a non-marking hose.

If you don't need extra high pressure hose then a single braid works well for most situations.  It's lighter, more flexible and a lot easier to roll up than a double braid hose.  As well, single braid is less expensive.  Most off the shelf pressure washers up to 4000 PSI come with single braid hose.

For Hot Water, use a hot water specific hose.  Look for markings that indicate the temperature rating and make sure you don't exceed it.  Having a hose filled with 3000 PSI hot water can do serious damage to you if it bursts.

Steam rated hoses are more expensive but well worth the extra money for safety sakes.  Never operate a machine in steam mode without making sure it is steam rated.

Most of the Big Box "hobby" washers use a thermoplastic hose.  These hoses usually have a fabric type braid, are cheap to make and usually not rated for more than 2000 PSI.  If you bend the hose too much it will kink and eventually fail at the kink . Trying to find someone to fix a kinked thermoplastic hose is difficult so be careful.

Most hoses have what's called "bend restrictors" installed at each end.  These help prevent exposure of the braid at the fittings to the elements.  

Many ask what effect using a longer hose on pressure and flow has.  It is a complicated process that I have never been able to understand.  Here is a description of how to do it if you are so inclined

• Pressure drop and flow rate calculation can be used for pressure drop and flow rate calculation for all newtonian fluids with constant density. You can calculate pressure drop or flow rate through a pipe including friction coefficient and local resistance coefficient K for valves and fittings calculation. The most frequently used calculation in fluid dynamics probably is the calculation of pressure drop through a pipe or a channel. Also when the difference in pressure is known the same calculation is used to calculate flow rate through pipe. Pressure drop calculator for closed pipe is based on the Bernoulli equation for calculation of pressure difference between two points of pipe, including pressure losses due to friction and local pressure losses in valves and fittings. Pressure drop calculator can be used for both laminar and turbulent flow regime. It can calculate pressure drop or flow rate through a pipe including friction losses and local pressure losses calculation. Pressure drop calculation due to friction is using friction factor values and pressure drop due to local resistance is using resistance coefficient K for valves and fittings values. Flow mean velocity calculation for known flow rate and pipe diameter is also used in calculator. Values of Reynolds number and flow regime - laminar or turbulent are presented.  

Or, you can figure on losing 1 pound per foot under average conditions!