Is it possible to consume a webservice whit Zoho API?

Hi all,
I am new in Zoho and I don't know the API possibilities yet. I have a client that uses Zoho and he wants to obtain data from another application. I thought about the possibility to make Zoho call an webservice to fetch data from my application.
My doubt is if I can use the Zoho API to do this. Does Zoho has this active behaviour? Can I make it to call an webservice to receive data?

Thanks for any tip.