Defines a skeleton of an algorithm in an operation and allows subclasses to redefine certain
steps of an algorithm without changing the algorithm's structure.
Example:
For instance CV form has blanks to fill in with your name, surname, work experience etc.
CV structure does not change itself, only data is different. Another example instruction/algorithm
of making coffee is the same as of making tea, only one step differentiates them. Instead of coffee you
need to put tea bag in a cup than pour boiling water and add sugar to taste.
