Copyright is defined by the Oxford English Dictionary as "The exclusive right given by law for a certain term of years to an author, composer, designer, etc. (or his assignee), to print, publish, and sell copies of his original work."
"copyright, n. (and adj.)." OED Online, Oxford University Press, June 2017, www.oed.com/view/Entry/41314. Accessed 13 December 2017.
In simpler terms, this means if you create something and obtain legal copyright to the creation, you obtain control over its use. Makes sense, right?
Remember though, copyright is a LEGAL term. Just because you create something does not always give you legal ownership of it.