Bicycle front suspension types What is the difference between these two front suspension types ?


and this type : 



On the upper the suspension seems stronger but is there any difference in the build type ? 

Please ignore the different branding and model.
This biggest difference is the top (Kona) is a Dual Crown fork where as the bottom image has a Single Crown fork. Dual crowns are generally found on downhill mountain bikes. The style has been copied down to department store bikes as well, but don't let the look fool you those forks are still only as good as what you paid for them. For a while, there were some lesser travel dual crown forks made (old Specialized Enduros had them).

Both of these forks are most likely coil-sprung, meaning they rely on a spring to produce suspension and not air being compressed. Both also probably possess some degree of adjustment such as rebound or damping (or none at all).

As for use, the dual crown is meant to handle more rough terrain and jumps/drops as it is more stiff and tortionally rigid. The upper crown also helps to remove force from the steer tube. Single crowns are found in travel ranges of 80mm-170mm and can be meant for anything from XC to aggressive freeriding.