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'.
1 In probability and statistics, the bar may be used to denote the sample mean of a random variable. 2  In many branches of math, the bar may be used to denote the closure (however it is defined) of a substructure of a mathematical structure.  The bar is also used to denote the conjugate of a complex number.