A builder`s level is set to plot the elevations of a lot. A sight on the level rod at corner A reads 6.1`. Corner “B” reads 5.6`. What is the difference between corner “A” and corner “B”?

A builder`s level is set to plot the elevations of a lot. A sight on the level rod at corner A reads 6.1`. Corner “B” reads 5.6`. What is the difference between corner “A” and corner “B”?