Consider going into Bitcoin mining as a business your setting up.
Putting it in literal terms if your were to mine for gold you would consider your mining equipment eg: bulldozer, filtering equipment and operating expense such as fuel to keep your machine going.
In the world of digital mining you would work with the same principle if you decide to venture into mining. In this case the equipment you’d need is a rig. A powerful computer your fuel would be electricity to keep your operations going. The purpose of your computer is to make its contribution in helping solve mathematical equations that in turn provides you with a reward in this case a Bitcoin or a fraction of the Bitcoin.
Keep in mind as you progress through Bitcoin mining. The mathematical equations will vary in difficulty. Your bitcoin yield will also vary depending on the contribution of your machine. As your are teamed up with other miners who are sharing as well thier equipment resources in solving this mathematical equations in order to gain Bitcoins.