Correct red line or its foreign analogue?

Question

Design

Here is my question.
I don’t remember where I found the information, I just know that it’s better to use an indent between paragraphs instead of a red line.
So what is the name of that indent?
It has a specific name and reasons why it is used, I remember that, but I do not remember the name of the indent itself.

Answer 1

In English I found: paragraph leading, paragraph spacing.
In Russian, it seems to be "interval between paragraphs."