"Referring to" something has two meanings:

It can mean to look at something to get information. For example, when you're cooking you can "refer to" a recipe to understand how to cook something. People can also refer to:

• Wikipedia
• your notes
• a chart
• a textbook
• the manual

The other meaning of "refer to" is to talk about something. Here's an example: Your friend starts telling a story about another friend of his. He doesn't say the name of this friend, but you think you know the person that he's talking about. You can say:

Are you referring to Yuuta, by any chance?

So you can see that "referring to" something means talking about something that you haven't directly said the name of.