To add bitcoin to your wallet, you first need to send bitcoin to an address that your wallet creates. You might already possess bitcoin in another wallet, and if so, you can transfer it from the wallet to your new one. Alternatively, you could purchase bitcoin from an exchange, a Bitcoin ATM, or peer-to-peer from someone you know personally.
Regardless of the source, they will request a Bitcoin address to send to. A few seconds after the sender has transferred the bitcoin, you can verify its impending arrival as your wallet is able to monitor the transaction while it is broadcasted to the network. You can further confirm the safe arrival of the funds when your wallet displays the transaction as having received "confirmations." The security and irreversibility of a transaction increase with the number of confirmations it has received. Transactions that have received a minimum of six confirmations are generally considered to be final and highly secure.