What is Data bases from Library??

Hi

I got a problem with my homework assignment. It's a group presentation, I and my group are going to research information about tuition's cost in US. My part is looking for information about tuition of university out of state. It said group must use credible sources ( using data bases from Library) and provide a work cited list. I know how to provide a work cited but

What is data bases? How can I find it? Do I need to go to my School's library for data bases?

From my knowledge. Data bases is the information can be trusted, and proved by evidences. Is data bases from Library mean all the information I found need to be from my school website?

Any ideas?

Learning English

I am Vietnamese. I need some one to help me with my English, specially with conversation. I can help you with Vietnamese language or culture. 

when do we use the words measurement and measure I just confused that how and when do we use the words measure and measurement?