Advantages:
Cost and convenience...You only pay for the storage you use.
Availability...Your work is available anywhere you go.

Concerns:
Reliability...You need internet to access the network.
Security...Your work is stored on a hosts server you don't know what security they have.
Software...The host might not have set up the most up to date software.
Potentially lower performance...As the host is else where (a different country!)

SAAS-Software As A Service:
At school you use software like Word, Excel and Photoshop. All these packages of software take up space on your computer's disk drive. When you want to use them, they load into the computer's memory and are run from there.

IAAS-Infrastructure As A Service
As SAAS is offered to you by another company, so is Infrastructure As A Service. IAAS is simply STORAGE and the most obvious examples of this are companies that store your photographs like Flikr, and companies that stream music or films.
The impact of IAAS is that you no longer have to upgrade your computers or phones as you did in the past. Instead of your phone getting full of photos, they are saved on the cloud for you.

NETFLIX is a company that offers you films. They host films on their cloud and when you log in, you can STREAM the film to your computer, smart phone or smart TV. This means that you don't have to worry about the storage space on your phone. Indeed, smart TVs have very little storage space so you have to stream the films. You simply don't have the storage space to save films.