In the real world, graphs are used to help people quickly understand and use information. Examples include graphs used in medicine and in business.
Medical graphs are used to collect information about patients, such as graphs showing a 1 to 10 pain scale for patients after surgery. These charts can help doctors and nurses quickly assess the effectiveness of pain medications and help doctors determine when to adjust medications as needed for a patient's comfort.
In business, charts are used to collect and present data used to evaluate the effectiveness of sales campaigns and to assess other aspects of daily business functions, such as comparing expenses to revenues earned.