A private placement memorandum is like a special book that someone makes when they want to ask for money from certain people. This special book has a lot of information in it, like an instruction manual for how to give money to the person who made the book.
The people who make the special book want to make sure that they are really, really interested in giving their money. That's why they only give the special book to a few select people who they think might want to give them money.
The special book has all kinds of information about the person who made it and why they need the money. It also says how much money they want and how long they will keep the money before they pay it back.
The people who get the special book can read it and decide if they want to give their money to the person who made it. They can also ask questions and get more information before they decide.
Once someone decides to give money to the person who made the special book, they sign a special paper that says they agree to give the money. This is like a promise to the person who made the special book that they will give them the money they need.
All of this happens in secret because the people who make the special book want to keep it private. They only want certain people to know about it because they want to be sure they can trust them with their money.