A tremor, or shaking, usually begins in a limb, often your hand or fingers. You may notice a back-and-forth rubbing of your thumb and forefinger, known as a pill-rolling tremor. One characteristic of Parkinson's disease is a tremor of your hand when it is relaxed (at rest). Slowed movement (bradykinesia).
The vertical bar is often called a ' pipe '. It is often used in mathematics, logic and statistics. It typically is read as 'given that'. In probability and statistics it often indicates conditional probability, but can also indicate a conditional distribution. You can read it as 'conditional on'.
vertical suggests a line or direction rising straight upward toward a zenith the side of the cliff is almost vertical. perpendicular may stress the straightness of a line making a right angle with any other line, not necessarily a horizontal one the parallel bars are perpendicular to the support posts.