The word *ci* has three main meanings:

* The clitic version of the second person plural [object pronoun](https://en.wikibooks.org/wiki/Italian/Pronouns#Object_Pronouns) (both direct and indirect). In this context it has a meaning roughly similar to the English *us*. For example
> Il cane ci ha morso
>
> *(The dog bit us)*

* The second person plural [reflexive pronoun](https://it.wikipedia.org/wiki/Pronome_personale_in_italiano#Pronomi_personali_riflessivi). Those pronouns mainly indicate that the verb is in the [reflexive voice](https://en.wikipedia.org/wiki/Reflexive_verb). In this guise it often plays the role of the English word *ourselves* or the word *each other*, for example:
> Ci divertiamo
>
> *(We enjoy ourselves)*
>
> Ci baciamo
>
> *(We kiss each other)*

 Note that in English the reflexive voice is often expressed by the *lack* of pronouns or by adding the possesive adjective to the object. A full treatment of the reflexive voice in Italian deserves its own question, so if you're interested don't hesitate to ask!

* As an adverb. In this case it has the same meaning of the English word *there*. 
> Ci sono andato
>
> *I went there*

The example you link to falls in the third usage, although as a fixed expression it might be a bit complicated for a beginner to figure it out. The meaning is as follows
> Che ci vuoi fare
>
> *What do you want to do* ***about it***

In this case *ci* has a figurate meaning, so rather than a physical location it indicates the whole situation you are speaking about. This particular sentence is often used to indicate resignation in the speaker (as in, *There's nothing we can do about this*).

For further examples, please take a look at [this answer](https://italian.stackexchange.com/a/30/1818).

**PS** Since in the question you indicate that you think that *our* is a translation of *ci*, I would like to point out that this is incorrect: the more correct perspective is that both *ci* and *our* can be markers of the reflexive voice. Even in those cases *ci* can never be replaced by *our* in the same position of the sentence.