Most people think you need to download winRaR or 7zip but actually you don't. They also think it takes forever and is really hard to download them but that's not the case. So I will tell you how. First you will need to download the map you want. After it is finished downloading open it up. There should only be one file inside it so right click it and click copy. Then, open your .minecraft file. The easiest way to open .minecraft is to go into Minecraft and click "Resource Packs" which is in the options. After you click Resource Packs open up the resource pack folder and it should say .minecraft next to Resource Packs at the top of the screen. Then, you have to open a folder titled saves. These are all your saved levels. Finally, you have to paste it in and it should appear at the bottom of your list of Minecraft worlds in Minecraft.