Intellectual property consists of the property of something intangible, including the property of copyrights, patents, trademarks, moral rights, etc. There are two main categories of intellectual property: industrial property (consisting of patents for inventions, trademarks, industrial designs, etc.) and copyright (consisting of musical works, written works, performance works, etc.).
Creative commons (CC) is a form of releasing that copyright from a work and allowing it to be used freely by others in their work. Credit can be given to the creator of the work (it is appreciated!) but it is not required. This allows for more widespread distribution of pieces of work, as well as the building upon of pieces of work. Below is an image that I found on the creative commons website. It does not require credit, however I have linked to the website below as well.