Steps are defined as a support for the foot of a person who is ascending or descending. This means that when a person is walking up or down a stairwell, each time he moves onto the next platform, he moves to the next step. The stairwell is a collection of multiple steps.
The word "stairs" is a shortened version of "stairwell." When somebody refers to stairs, he is speaking of a stairwell or a collection of steps that leads upward or downward. Stairs may refer to an entire collection of steps in a building, or they can simply refer to a collection of steps between flights.
One example of properly using "steps" is found in this sentence: "The woman climbed each of the steps as she raced up the building." Notice the sentence refers to the steps as individual items, not a collection. Another example: "The boy skipped steps as he ran down the stairwell."
The following sentence provides a proper example of how to use the word stairs: "The couple shopping for a new house knew they didn't want to buy a home with stairs." You can use steps and stairs together in the same sentence:. For example: "She couldn't believe how many steps there were on the stairs."