If you have a modern GPU in your computer or laptop, you can use it to significantly increase the speed at which Cycles processes a scene. Nowadays, you can use both hardware from Nvidia or AMD to get faster results, and Cycles will send all processing to those devices.
To use a GPU, you will first have to make sure that Blender recognizes your device. Go to the Edit menu and choose User Preferences. There, choose the System tab and look for the Cycles Compute Device options, as shown in the following screenshot:
After you check that Cycles can use your device, you must also set the performance settings to ...
