When dragging objects around the canvas and moving them next to other objects, you'll see alignment lines pop up. These have the smallest bit of magnetism to help snap your objects into alignment with their neighbors.
The app essentially makes its best guess about where you may want to place your object. But, if you want free rein with your object, you can temporarily bypass the alignment lines.
To override alignment lines when moving an object: simply hold Command (Mac) or CTRL (Windows) while dragging your content. You can then freely move your object around without any lines or auto-alignment magnetism.