Your bitcoin wallet is used to store bitcoins and, for all intents and purposes, can be regarded as a bank account. There are three types of bitcoin wallets; an online wallet, a mobile wallet and a software wallet via a bitcoin client.
A software wallet can be downloaded onto your computer via a bitcoin client. The big disadvantage with this is that it necessitates the download of the full bitcoin public ledger (blockchain), which can take days. And, although it gives you total control over your wallet, you still have to administer the security for yourself.
Online wallets are universally accessible and can be created on various websites. An online wallet is not managed by you personally, but rather taken care of by a third party who additionally has responsibility for its security.
A mobile wallet enables you to place your bitcoins in your pocket and effectively take them with you wherever you go. You can readily make payments in physical stores by scanning a QR code or holding your phone to a cash register equipped with NFC (Near Field Communication).
Please visit Bitcoin.org if you require more information before selecting a bitcoin wallet.