FPGA is the acronym for Field Programmable Gate Array. As its name implies, these embedded devices can be re-programmed on the field according to requirements. FPGA devices have lots of logic gates that can be synthesized using a hardware description language (HDL) like Verilog and using a tool/IDE would ease this synthesis job.

Unlike other programming languages, in HDLs; there is nothing prepared to execute for the CPU since there is no CPU basically. Instead, necessary logic gates are connected to each other to perform a function specific function. Since, these gates are only connected to perform some known functions only, it could perform faster than a CPU with a much less cost. 

Re-programmability comes with a trade-off though. FPGAs are generally slower than Application Specific Integrated Circuits (ASICS). However, some FPGAs may perform on par with their ASIC counterparts (where multiple ASICS combined to provide the functionality that these FPGAs do).