Proof of Stake (POS) was created as an alternative to Proof of Work (POW), supporting cheaper and faster transactions, by requiring a certain amount of coins to be locked up in order for the network to reach consensus. POS is seen as less risky in terms of the potential for miners to attack the network.
Proof of Work (PoW) lets one party proof the execution of an algorithm to another party. In the Bitcoin PoW system miners proof the validity of the transaction in a block. This way, the PoW consensus algorithm solves the 'double-spending problem' making it impossible for one party to create new Bitcoin without the agreement of the other participants.
A cryptographic key that is used with an algorithm to encrypt and decrypt data. A Bitcoin private key let's you access funds in a wallet.
A peer-to-peer (P2P) network in which interconnected nodes ("peers") share resources with each other without the use of a centralized administrator. The Bitcoin network is peer-to-peer.
A piece of paper containing a private key or mnemonic phrase to unlock a cryptocurrency wallet.
Software that is open for anyone to modify, copy, share or build upon. The code for blockchains like Ethereum and Bitcoin is Open Source, for anyone to verify and improve it.
A Bitcoin node is a server that downloads the history of transactions and shares it with other nodes in the network.
Also multisig. While normal bitcoin wallets need only one private key to make a transaction, multisig wallets need keys from multiple parties. Other blockchains, like Ethereum, provide advanced multisig features, like setting different permissions per users and apps.
Thousands of miners compete on the reward which is only paid once per block. Miners who join a mining pool promise each other to share the reward equally, making the reward more predictable.
Miners secure the network, by ordering Bitcoin transactions into blocks and verifying the blocks of other miners. For this work, miners get rewarded with transaction fees and newly issued bitcoins.