Creative commons-give people the right to share,use and modify.

Creative common is a non profitable organization that provide free stuff and material that we can use and share legally with out any problem.It release copyright licences as "Creative common licenses" which can be used with free of charges.
Basically,You should use images,video,text,etc for your blog,social media,youtube which are free and are not restricted to use.By using "free for use" stuff you are not violating any laws in the internet and you don't have to worry about copyright infringements
So,creative common is organization which provide you with search links to the stuff which can be used by any one in the internet for free.
Note:The credit for the matter still goes to the original creator of that matter,you cannot say that you have created that matter.These are not"All copyright reseverd"but this are "some copyright reserved",that means you can use this but you cannot sell this.
learn more by going to this website "About Creative common".  

To get the "reuse with modification" material,  type creativecommons.org ,At the bottom and below Explore you will find "Find CC-Licensed works".here creative commons will provide you with links to the site containing re useable material,click here Creative commons.you will notice that creative commons has provide site like google,youtube,flickr,soundcloud,etc.click on one of the link and type the thing you want to search for.

example let us search for this image of "Creative common"

1. select google images link in creative common website's search using-google images.
2. next type Creative commons in the search bar in the "Enter your search query". 
3. now it will direct you to google images site which contain the images of "Creative commons" which are free to use and share.

You can also search for other thing in the other links provide by creative commons.

support the creators by not using them for your commercial purpose.
share this information with others on other platforms and social media.