Node = Connections to the coins network.
Scrypt
PoS
PoW
X11,X13 = Algorithms for all kinds of coins. Bitcoin is a POW (Proof of Work)
There is a ton more info but that's the basics.
PoS and PoW are not hashing algorithms, they are different ways to prove that coins exist, and where in the blockchain. PoW stands for Proof of Work, and it's what Bitcoin uses. People mine Bitcoins by letting computers "guess" the right hash many many millions of times per second. When they guess correct, a block is found and gets added to the blockcchain.
Many people consider this an unsustainable way to secure the network due to power costs.
PoS tries to solve this.It stands for Proof of Stake. There is no mining ; instead, people who have coins already get "stake" which is like interest in a bank account.
I suck at explaining it well so here is a link
https://en.bitcoin.it/wiki/Proof_of_StakeOh one good parting piece of advise : don't buy altcoins unlike you enjoy gambling and dont mind going broke