There are 5 parts of a box-and-whisker plot.
Lowest Value (Minimum)= that's the left end of the graph, and shows what the minimum value is. Here, the minimum is 46.
Lower Quartile (Q₁)= This is the left edge of the "box" in a box-and-whisker plot. Here it is 55.
Median (Q₂)= This is the line in the middle of the box, and represents the very center of minimum and maximum values. Here it is 58.
Upper Quartile (Q₃)= This is the right edge of the box in a box-and-whisker plot. Here it is 63.
Highest Value (Maximum)= This is the farthest right point on your plot. Here it is 66.
Hope this helps! If you have any questions, please feel free to ask in the comments below!