Shift the verb and shift the noun are very similar in meaning. A shift is a change in something or an adjustment in the way something is done. You can either make a shift (that's the noun), or you can just shift (that's the verb).
What makes a shift different from, say, a change is that it implies some kind of movement; a sense that the thing that you're shifting is still the same thing, just moving in a different direction. For example, when you shift gears in a car you're simply moving from one gear to another. If you shift your focus, you're still focused, but the focus has moved. If the government shifts its policy, that policy, while different, is still a policy.