List some important ideas that the giver includes. why did you choose those ideas?

I'm assuming you mean the book :)
The Giver champions the idea that differences give us life.  This is an incredibly important message, because differences are often stifled by society.

Another important idea in the book is the exploration of what would happen if the government took away our knowledge of history.  This would drain us of a lot of power.

Because it changed the way poeple lived back then