Similarity: periods and groups are distinguished in the structure of both tables. There are 7 periods. The main subgroups are designated by the letter A, and the secondary ones are indicated by B.
Difference: in the short-period version, the system has rows, and in the long-period version, they are absent. Therefore, in the short-period version of the table, there are 8 groups, which are numbered with Roman numerals from I to VIII, and in the long-period – 18, which denote either Arabic numerals or Roman numerals indicating the A- or B-group, similar to the short-period version. In the short-period version of the table, the main and secondary subgroups are also distinguished by the placement of the element (to the left or right of the center of the cell).
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.