Website: Eth Gas Station

 ethgasstation.info

This website estimates gas fees.

Etherscan

Etherscan can be used to see what's going on with a crypto wallet. Just enter the address of the wallet into Etherscan.

DAO - decentralized autonomous organization

Oracles

Smart contracts are often paired with oracles to interact with the real world or the outside world. These types of smart contracts are called hybrid smart contracts.

An oracle network can allow smart contracts to obtain real-world data, or perform external computations, etc.

Smart contracts - self-executing code in blockchain

Smart contracts are a set of instructions that when placed on a blockchain, are a self-executing piece of code. This allows for trustless agreements to be formed.

Blockchains are transparent.

 Everyone can see everything that happens on a blockchain.

Trustless

 Trustless = you don't need to trust any party.

Smart contracts, blockchain, and decentralized apps allow our transactions to be trustless.

Immutibility

 Immutable = cannot be changed

What is a crypto wallet and how does it work?

 A crypto wallet is actually a piece of software that:

(1) Stores our private keys and public keys.

(2) Can interact with the blockchain.

(3) Can send and receive crypto.

[Note: the features listed above are common features found in many crypto wallets, but whether or not a particular wallet supports all of the above features depends on the wallet software. Different wallets may have different features.]

It is important to know that our crypto is not actually stored in our wallets. Our crypto lives in the blockchain, and wallets are software that makes it easier for us to access and manage our crypto.