Remember that the bitcoin exchange and the bitcoin wallet are not the same things. Bitcoin exchanges are similar to foreign exchange markets. The exchanges are digital platforms where Bitcoin is exchanged for fiat currency—for example, bitcoin (BTC) for U.S. dollars (USD). While exchanges offer wallet capabilities to users, it is not their primary business. Since wallets must be secure, exchanges do not encourage storing large amounts of bitcoin or for long periods. Therefore, it is advisable to transfer your bitcoins to a secure wallet. Because security must be your top priority when choosing a bitcoin wallet, opt for one with a multi-signature facility.
After you’ve set up your wallet with a payment method, you'll need a place to actually buy bitcoin. Users can buy bitcoin and other cryptocurrencies from online marketplaces called “exchanges,” similar to the platforms that traders use to buy stock. Exchanges connect you directly to the bitcoin marketplace, where you can exchange traditional currencies for bitcoin.
Once you have a bitcoin wallet, you can use a traditional payment method such as a credit card, bank transfer (ACH), or debit card to buy bitcoins on a bitcoin exchange. The bitcoins are then transferred to your wallet. The availability of the above payment methods is subject to the area of jurisdiction and exchange chosen. Below is a screenshot of the bitcoin interface on Coinbase showing how to buy and sell bitcoin and also Bitcoin Cash, Ethereum, and Litecoin, which are other popular virtual currencies. The user clicks the "Buy" tab to buy digital currency and the "Sell" tab to sell digital currency. You select which currency you are buying/selling and which payment method (your bank account or credit card) you want to use.