There is a lot of information on this but, just as people who bleat "5 a day" without context, results can vary.
After all with no other context or guidance 5 friut and veg a day could be two bags of crisps, a bag of chips and two sweetened fruit juices.
Context is everything.
There is more info
here if you are interested.
But the short version is this. Ambling around the house are wasted steps. Steps which are continuous and "brisk" are the most beneficial. So going out and briskly walking 1 mile, twice a day, will meet the 4,000 steps and do a lot of good.
Walking 1,000 steps up stairs will give more benefit than 4,000 walking briskly down the street.
Before going for an all encompassing number you have to understand what that number means, how you should do that number of steps and under what conditions.
Without that, as WM says, the entire number of steps is meaningless. You are back to 2 bags of crisps, bag of chips and two sugary orange drinks.