A walk-up apartment is an apartment located in a building accessible only by stairs. There's no elevator to reach the upper floors of the building — just your legs and lots of steps.
Walk-up apartments can be a lot of work so they might seem less desirable. Due to the low demand, that means they can be more affordable — even in an expensive city like Manhattan.
Buildings with walk-up apartments are usually smaller and have fewer tenants, giving you a more private living situation. And you can ditch the gym membership since you'll be getting your exercise every day via the stairs.
But there are lots of obvious downsides to a walk-up apartment. If you decide to move into one, it'll be difficult hauling all of your furniture up multiple flights of stairs. It can be tiring walking up and down stairs each day and even worse if you're someone who's bouncing in and out of the house regularly.
Whether or not a walk-up apartment is right for you all comes down to your perspective. What one person views as a pro might be viewed as a con to you or vice-versa. Make sure the pros outweigh the cons from your perspective before moving into a walk-up apartment.