Traditionally, when you transfer money through a bank, you need to know the bank account number of the intended recipient. With cryptocurrencies, a wallet address is analogous to a bank account number.
You can generate a wallet address through an official wallet client or obtain one from a cryptocurrency exchange by registering an account with them. For specific coins, we recommend you refer to relevant resources included in the mining guides.
Wallet addresses are not universal; you must use different respective addresses for different coins.