FPGAs are synchronous digital logic. That may sound complicated but it's actually conceptually quite simple. If I had a white board I could show you a diagram i

FPGAs are synchronous digital logic. That may sound complicated but it's actually conceptually quite simple. If I had a white board I could show you a diagram in 10 seconds that would probably clear everything up. But instead here's my attempt at a description. 1- digital logic. From your CS background you're familiar with AND, OR, NOT, etc... imagine having a bunch of these simple functions and being able to combine them and reorganize them to meet your needs. These functions are "continuous " in that they always update their output when their inputs change. 2 - synchronous: this essentially means "registers" that store values (flip flops) are controlled by a global clock signal. When the clock "triggers" (usually on the rising or falling edge) new values are loaded into the registers. So with those definitions in mind, an FPGA, or any other synchronous digital system, can be thought of as: inputs feeding registers, feeding a cloud of logic, feeding registers, etc... for as many stages as is needed (or possible) until you get to the outputs. Edits: clarifications (hopefully)