Sensory adaptation is when our senses become less responsive to a constant stimulus. For example, after wearing a strong perfume for some time, you may no longer notice its scent.
Habituation is when we become accustomed to a particular stimulus and stop responding to it. An example would be getting used to the sound of traffic outside your window and no longer paying attention to it.
Tolerance refers to needing higher doses of a substance (e.g., drugs) over time in order to achieve the same effect. It is often seen in drug addiction where individuals require larger amounts of the substance for it to have an impact on them.