A node is a full client that has the entire blockchain and relays transactions/blocks across the entire bitcoin network. When your bitcoin client is syncing to catch up to the last block, you are downloading the blockchain from other nodes.
So if I understand correctly more nodes means faster downloading of the blockchain and possibly faster processing times as well for transactions? More nodes are good?
I don't think we need more nodes atm
More nodes don't speed the confirmation time
Nothing speeds confirmation time except for a protocol change (extremely unlikely) and miner's luck (not permanently). Technically a decrease in difficulty could do this as well, but only temporarily and theoretically.
More nodes = more decentralization = more security for the network.
