This is a tutorial on naming something on Minecraft (PC and mac edition).
Step 1: Obtaining the Nametag
First, you need to select an anvil (The crafting recipe is above). A nametag can be obtained in creative by selecting it or you can catch it from the water with a fishing pole. Keep in mind that it is a very rare catch. You can also find it in dungeons.
Step 2: Place the Anvil
Next, you need to place the anvil. On the PC or mac, you can right click the mouse to place the anvil.
Step 3: Selecting the Name Part 1
Now, you put the nametag in the farthest slot to the left in the anvil.
Step 4: Selecting the Name Part 2
Then once you have finished typing the name, it will appear in the farthest to the right slot in the anvil. Under that you will see how much enchanting points it will take to name.
Step 5: Naming the Animal
Then you hover your crosshairs (The plus looking thing in the middle of your screen) over the subject making sure your nametag is selected in your hotbar (The thing on the bottom of your screen).
Step 6: Completion
You right click the subject and bam, your subject is named!