Some characters are not on the keyboard—for example, the copyright character (©). To type these letters in Vim, you use digraphs, where two characters represent one.

To enter a ©, for example, you hold CTRL key and press K, and then type Co.

To find out the entire list of digraphs that are available, use the following command:
:digraphs

or the shorter version of the command:
:dig

You will see a list of command like the following screen shot:

For instance, in the list, A' Á 193 means that if you want to type Á symbol, you
1. hold CTRL key and press K
2. and then type A'
3. you will get Á
4. 193 is just the character number for your reference.

Hope this helps! :)