ethgasstation.info

 A site that estimates the gas for a transaction.

Units converter - Ethereum

See how much a certain amount is in Wei , Gwei, and Ether units.

eth-converter.com

Gas

Gas: awarded to node operators for successfully including a transaction on a blockchain (adding a transaction to a blockchain).

The amount of gas a certain transaction requires depends on how "computationally intensive" that transaction is, for example, sending crypto to one address would require less gas than sending crypto to 100 addresses.

Gas: measure of computation use

Gas price: how much it costs per unit of gas

gas limit: maximum amount of gas for a transaction

transaction fee: (gas used) x (gas price)

for example:

16,000 gas @ 1 GWEI per gas = 16,000 GWEI

Gas prices fluctuate based on demand on the blockchain.

Source:

Patrick Collins

https://www.youtube.com/watch?v=M576WGiDBdQ&t=191s

Etherscan - a block explorer

 A "block explorer" is an application that allows us to view transactions on a blockchain.

Etherscan is an example of a block explorer.

Faucet - Rinkeby

 faucet.rinkeby.io

A faucet is an application that gives free tests tokens for testing use.

Test networks:

Rinkeby

Ropstem

Kovan

Goerli