To answer your first question - yes, ASICs (application specific integrated circuits) are generally hardwired - once the hardware is burned into the silicon, it

To answer your first question - yes, ASICs (application specific integrated circuits) are generally hardwired - once the hardware is burned into the silicon, it can't be changed. On the other hand, FPGAs (field programmable gate arrays) are, as the name suggests, reprogrammable. In order to allow this (in a useful way) FPGAs are built of a large variety of logic gates which can be connected together by the programmer to, essentially, simulate a pure hardware circuit. The tradeoff is that ASICs are (almost always) much faster at performing their specific task than an FPGA could be - I'm not sure of all the reasons, but you could imagine that there are many, many optimizations that you can do when designing pure hardware that don't transfer over to software-defined-hardware, because you have the FPGA intermediary there