What is a generation-skipping tax(GST)? Why it is introduced in the first place?

In brief, it means that one's property will be passed down only a couple of generations, and anything that past will make that person subject to the tax especially when he or she gives a large amount to their grandchildren. This is because, the first time that Congress voted for the estate tax, the taxpayers came up with different ways to avoid paying taxes and putting the assets in a trust was one of them. The trust said that passing down the generations, children will get the income from the trust until they die.  But because the children down the generations never actually received the assets then it was never in their estate. Therefore, trusts would sit in limbo in no one’s estates for possibly a long time, maybe hundreds of years!