Mastering Ethereum

Chapter 2. Ethereum Basics

In this chapter we will start exploring Ethereum, learning how to use wallets, how to create transactions, and also how to run a basic smart contract.

Ether Currency Units

Ethereum’s currency unit is called ether, identified also as “ETH” or with the symbols Ξ (from the Greek letter “Xi” that looks like a stylized capital E) or, less often, ♦: for example, 1 ether, or 1 ETH, or Ξ1, or ♦1.

Tip

Use Unicode character U+039E for Ξ and U+2666 for ♦.

Ether is subdivided into smaller units, down to the smallest unit possible, which is named wei. One ether is 1 quintillion wei (1 * 10¹⁸ or 1,000,000,000,000,000,000). You may hear people refer to the currency “Ethereum” too, but this is a common beginner’s mistake. Ethereum is the system, ether is the currency.

The value of ether is always represented internally in Ethereum as an unsigned integer value denominated in wei. When you transact 1 ether, the transaction encodes 1000000000000000000 wei as the value.

Ether’s various denominations have both a scientific name using the International System of Units (SI) and a colloquial name that pays homage to many of the great minds of computing and cryptography.

Table 2-1 shows the various units, their colloquial (common) names, and their SI names. In keeping with the internal representation of value, the table shows all denominations in wei (first row), with ether shown as 10¹⁸ wei in the 7th row.

Table 2-1. Ether denominations and unit names

Value (in wei)