When people talk to each other, they use different words to show respect and politeness. In the Russian Empire, people had different ways of addressing each other depending on their status and relationship.
One way of addressing someone in Russia was using their first name and patronymic. A patronymic is a name that comes from the father's first name. So, if someone's father was named Ivan, their patronymic would be Ivanovich (for boys) or Ivanovna (for girls). For example, if you were speaking to a man named Mikhail whose father's name was Ivan, you would call him "Mikhail Ivanovich". This is a polite and respectful way of addressing someone.
If someone had a higher status than you, you would add a title to their name. For example, if you were speaking to a professor named Ivan, you would call him "Professor Ivanovich". If you were speaking to a prince named Nikolai, you would call him "Prince Nikolai".
For members of the imperial family, there were specific forms of address. The emperor was addressed as "Your Imperial Majesty" or "Your Majesty". The empress was addressed as "Your Imperial Highness" or "Your Highness". Their children were addressed as "Grand Duke" or "Grand Duchess".
When addressing someone in writing, there were also specific conventions. A letter to someone of higher status would begin with "Your Excellency" or "Your Highness", followed by their name and title. A letter to a friend or family member would begin with "Dear" followed by their first name.
Overall, forms of address in the Russian Empire were an important way of showing respect and acknowledging social hierarchy.