"All Creative Commons licenses have many important features in common. Every license helps creators — we call them licensors if they use our tools — retain copyright while allowing others to copy, distribute, and make some uses of their work — at least non-commercially. Every Creative Commons license also ensures licensors get the credit for their work they deserve."
Learn more about the different licenses: Creative Commons Licenses
Image Database
Websites
Go to Search tools then Usage Rights
Label for reuse means you could use the images commercially, or non-commercially. Label for noncommercial reuse means you cannot use it for profit or publications. With modification means you can alter the image. And remember to also cite the image.