A battery is a little machine that uses chemicals to create electricity. They come in all shapes and sizes. You couldn't live without batteries, they power your alarm clock that wakes you up for work in the morning, the remote you use to turn on the TV when you get Home, and even provide electricity to your favorite toys as a kid.
There are two main types of batteries: disposable and rechargeable.
Disposable batteries can't be reused after they run out of juice. For example, if you've ever used an old flashlight and found it didn't work because the batteries were dead, those are disposable batteries. They're cheap, last a long time before needing a replacement, but once it dies—it dies. Though don't worry! They can be recycled.
Rechargeable batteries on the other hand can be plugged into something and brought back to life. Imagine recharging your phone after a day of browsing videos online completely drained it. The rechargeable battery is pretty self explanatory..
For now understand this: disposable = throw away after use | rechargeable = power up again