It really depends, as there are different sets to cater for any possible scenario! However, it's usually a combination of two or all three of these elements:
Crib
Essential to ensure a good and - hopefully - long night's sleep (although it won't work miracles), when purchasing it you can choose between:
Traditional crib: ideal if you're planning on using it again for their future siblings or if you're happy to invest in a new bed when your little one outgrows it;
Convertible crib: since one side can be removed and replaced with a safety rail, these cribs can grow with your child by becoming a toddler bed and, in some cases, even a full-size bed; while convertible cribs are more expensive, they're actually a wise investment that will save you money in the long run, and definitely worth it if you're not planning on having any more babies;
Dresser
This piece will be a lifesaver when it comes to storage space! Most models also include a removable topper that serves as a changing surface: a practical space-saving option if you're not planning on purchasing a separate changing table;
Changing table
Have you already got a large chest of drawers? Would you like to utilize the top of your dresser as an additional storage space? Or perhaps you have a rather large nursery that you'd like to fill with more pieces? Then you might want to consider choosing a nursery furniture set that includes a separate changing table;
Whether you opt for a model with drawers or one with open shelves, this practical piece of furniture will also provide some extra storage space.
Unless you already happen to have one of these items, buying a three-piece nursery furniture set is the handiest option.
However, if you're tight on space, we definitely recommend purchasing a two-piece set that includes a crib and a dresser with a changing top