Okay kiddo, so a long time ago in Iran (which was called Persia back then), when movies were first starting to become popular, the people making the movies wanted to tell stories about their own country and culture. This meant that they made movies in Persian instead of other languages, and they showed things like Iranian landscapes and customs.
Before the revolution happened in 1979, Iran was ruled by a king named Shah Mohammad Reza Pahlavi. The movies made during this time were usually about wealthy people or historical stories, but they weren't allowed to show anything that went against the government or religion. So, if someone wanted to make a movie about something controversial, they had to hide their message in the story or make it subtly.
There were many talented filmmakers during this time who worked hard to keep the cinema industry alive in Iran. Some examples are Abbas Kiarostami, Forugh Farrokhzad, and Mohsen Makhmalbaf. Many of these directors used their movies to question the government, religion, and social norms.
After the revolution happened, things changed a lot. The new government didn't like movies that challenged their authority or showed anything that they didn't like. So, the movies made during this time were more focused on showing the government and religion in a positive light.
However, some filmmakers continued to make movies that challenged the government or showed things that weren't allowed. These movies were called "underground cinema" because they were made and distributed secretly. Even though it was dangerous, many people still watched these movies because they wanted to see something different from what the government was telling them.
In conclusion, pre-revolutionary Iranian cinema was a time when movies were made to show the culture and stories of Iran. While there were limitations on what they could show, many filmmakers still used their movies to challenge the government and society. After the revolution, things became more restrictive, but some people continued to make movies that pushed boundaries.