leveling to objects along the same plane

as the title says, ive read through the manuel but cant figure out how to level two objects or edges along a plane.

how to level two objects or edges along a plane.
What does this mean ? Show a clear example of exactly what you want. Do you mean objects (different objects ?), just an edge or edges of an object, or rotating an object? Your wording is ambiguous so a specific question would help give you an appropriate answer

To align objects you can sue the ‘Simple Align’ addon or use the snapping options (magnet icon on 3dview header)

i would like to have the two circles leveled with eachother on the x y plane

i;m looking to level two circles on the x y plane with eachother at the same hieght so i can create a completely flat face between them. i was wondering if there was a tool to do this?

make one circle, press shift+d+z move your mouse. You now have 2 circles with the same x and y

Assuming the 2 circles are parallel to the XY plane, [SHIFT S] --> Cursor to Center. [PERIOD] to set the Pivot to the 3D cursor. Select all the vertices of the 2 circles. [S], Z, 0, [ENTER]