What is programmable logic in FPGA, fpga chip, Field-programmable gate array

 ProASICPLUS Series 150000 System Gate 158 I/O 3.3 V SMT FPGA - PQFP-208

https://www.futureelectronics.com/p/semiconductors--programmable-logic--fpga-flash/apa150-pqg208i-microchip-5082308