Programming is a verb, programming is equivalent to writing code, writing code in order to write a language that the computer can recognize, let the computer do what it wants to do instead of itself.
Field programmability is the product of further development on the basis of PAL, GAL, CPLD and other programmable devices. It appears as a semi-custom circuit in the field of application-specific integrated circuit (ASIC), which not only solves the shortcomings of custom circuit, but also overcomes the shortcomings of the limited number of gate circuits of the original programmable device.