Free content, or free information, is any kind of functional work, artwork, or other creative content that meets the definition of a free cultural work.^[1] A free cultural work is one which has no significant legal restriction on people's freedom:

• to use or modify the content,
• to distribute copies of the content,
• to distribute works derived from the content.^[2]

Although different definitions are used, free content is legally similar if not identical to open content. An analogy is the use of the rival terms free software and open source which describe ideological differences rather than legal ones.
Free content encompasses all works in the public domain and also those copyrighted works whose licenses honor and uphold the freedoms mentioned above. Because copyright law in most countries by default grants copyright holders monopolistic control over their creations, copyright content must be explicitly declared free, usually by the referencing or inclusion of licensing statements from within the work.
Though a work which is in the public domain because its copyright has expired is considered free, it can become non-free again if the copyright law changes.^[3]