The reason for a person to learn shorthand is to increase one's writing speed in order to fulfill the requirements of their job. This allows for the ability to take notes almost as fast as a lecturer can speak using a symbolic writing system. Thus one will be able to accurately report certain facts to those they are responsible to through writing a certain type of letter, a formal report, or an article of a particular kind.
Picking out one of the various systems that exist is one of the steps one needs to take to learn shorthand. Next one will have to practice that system through a series of drills and exercises. These exercise will most likely be assigned by the instructor that heads the class one is attending.
Some of the characteristics that many of these systems usually have in common are unique treatments used for vowels, abbreviations for frequently used phrases or words, and the recording of the sounds of speech rather than the spelling. Thus one of the first required lessons is the learning of all those symbols that are used.
One important lesson one will also be taught is the eliminating of words that are superfluous. In this way one will be able to get the important information down in a speedy manner in order to later refer back to it.
One lesson that is also common to one of these course is the treatment of numbers. Thus one will have the chance to record any number without the slowing of one's recording speed which may cause the loss of other facts that may be vital. A distinct advantage for those who are expected to be accurate in what they report.
Having to learn shorthand for one's career will allow one to be more efficient at what they do once they have completed their courses.
Their facts will also be more accurate in anything they will have to later report to those they are responsible to. Which will then give them a better chance at being properly recognized for a job well done.