Believe it or not, you have an estate. In fact, nearly everyone does. Your estate consists of everything you own: your car, home, other real estate, checking and savings accounts, investments, life insurance, furniture, personal possessions. No matter how large or how modest, everyone has an estate and something in common you cannot take it with you when you die.
When that happens (and it is if not when), you probably want to control how those things are given to the people or organizations you care most about. To ensure that your wishes are carried out, you need to provide instructions stating whom you want to receive something of yours, what you want them to receive, and when they are to receive it. You will, of course, want this to happen with the least amount paid in taxes, legal fees, and court costs.
That is estate planning making a plan in advance, naming the people or organizations you want to receive the things you own after you die, and taking steps now to make carrying out your plan as easy as possible later.