The other concept that is not easy to explain is logical order.
Logical order becomes significant when scripts that run in different directions are mixed.
This is a real example, from an RLIN record. The work is an Haggadah, the liturgical book for the Passover Seder, intended for Russian Jews who emigrated to the United States. The logical order internal order of the characters is shown in black. The arrows point to the first character, the Hebrew letter samekh. The last letter is the period.