Okay, so the impersonal passive voice is a way of talking about something without saying who did it. It's like when you say, "It's raining outside," instead of saying, "John made it rain."
Usually, when we talk, we focus on the person who did something. But, sometimes we want to talk about something without drawing attention to the person who did it. That's when we use the impersonal passive voice.
For example, let's say we want to talk about a mistake that was made at work. Instead of saying "Samantha made a mistake," we could say "A mistake was made." This way, we're not pointing fingers at anyone and it's more general.
Another example is when we talk about the weather. We say things like "It's hot today," or "It's snowing outside." We don't say "The sun is making it hot today," or "The clouds are making it snow." We use the impersonal passive voice to talk about the weather.
So, the impersonal passive voice is a way of talking about something without saying who did it. We use it when we want to be more general and not focus on a specific person.