It takes a certain amount of time for a signal to propagate through a series of logic gates (or other electronic components) within a chip, which are also depen

It takes a certain amount of time for a signal to propagate through a series of logic gates (or other electronic components) within a chip, which are also dependent on many other factors. In most synchronous chip design, you look at the worst (slowest) timing case for the design, and constrain your clock speed to that. You can break up critical (the longest/slowest) paths of a design through pipelining, which can be done manually, or through nice automated techniques like register retiming. Basically, you can add flops (as in D-flip flops, also known as registers) between sections of the design that can be broken into independent pipelined components. Example: Say you have a design that takes 10ns from start to end flops. This means the max clock speed for that component is 100MHz. If you are clever, you may be able to dice that up into 10 separate components, which are pipelined, meaning that while there is a 10 cycle startup latency, if you have continuous throughput you can run the design at up to 1GHz. Even better is that nowadays, synthesis tools can do automatic pipelining through something called register retiming. Without doing any work, you can tell the synthesis tool what clock speed you want to run at (or how many cycles you want in your pipeline), and it is able to automagically insert flops to decrease timing for the overall design.