You are partially correct.
"Tick-Tock" was a model adopted by chip manufacturer Intel Corporation from 2007 to follow every microarchitectural change with a die shrink of the process technology. Every "tick" represents a shrinking of the process technology of the previous microarchitecture and every "tock" designates a new microarchitecture. Every year to 18 months, there is expected to be one tick or tock.
What does this mean?
So here's the thing, every time a new architecture is introduced, we mainly expect an increase in IPC (instructions per clock). More IPC basically means that the CPU can process more information in a given time.
And then we have the refresh, ie improvement in manufacturing process while not really changing the architecture. Manufacturing process basically means the size if the transistors on the silicon chip. Hence, smaller manufacturing process leads to less power consumption and an increased ability to dope more transistors in the silicon chip.
But what does this mean for you?
It means that the 6th gen processor is waaay better at thermals and power consumption while giving much more power from under the hood.
Sandy bridge was great, had three highest IPC jump we've ever seen, but of course over the time, over several generations, it has become irrelevant. To even get the i7 2700k to i7 6700k performance wise, you'll have to overclock it to insane Hertz (probably 5ghz+). Not recommended.