hello friends,


i have a 2 part question;
it's being said that the states are stored into the blocks in ethereum. Shouldn't they be stored anyway? where are bitcoin states get stored if not in the block?


& What does this sentence even mean? >
"A special kind of tree known as a "Patricia tree" is used to accomplish this, including a modification to the Merkle tree concept that allows for nodes to be inserted and deleted, and not just changed, efficiently. " insert and deletion of nodes? what does he mean by that?

"Additionally, because all of the state information is part of the last block, there is no need to store the entire blockchain history"
is the state the only thing needed for trxs to be verified? he means knowing state is enough for what?