On the Planets tab on the picture the planets are shown as they are situated on the sky currently in your city. For the right planet display select your city on Your Location tab.

Point Z is the zenith (the highest point over the horizon), N S W E are the cardinal directions. Edges of the horizontal plane there cardinal directions are marked is the horizon.

To change the visibility scopes right click on the picture and drag to the left or to the right. One half of the horizon is shown, that is 180°. If the planet is darkened, as the Moon or Mars on the picture, it is behind your back if you look directly

Selecting the planet in the dropdown list or clicking it on the picture you will see its azimuth and altitude in the upper line, real time changing.

Azimuth is the angle of the planet location in the horizontal plane from the North point clockwise (to the East). Changes from 0° to 360°.

Altitude is the angle of the planet location in the vertical plane up or down from the horizon. Changes from -90° to 90°. For instance, 0° is the point on the horizon plane, 90° is the zenith. Negative altitude is the altitude of the planets which are lower than horizon, that are the planets which cannot be seen on the sky.