Copyright

Copyright is a legal principle that grants creators—be they writers, artists, musicians, photographers, or other sorts of content creators—exclusive rights to their original works. What this means, in effect, is that the creators have control over what happens to their works, in terms of use, sharing, distribution, or reproduction. Content that you might come across while browsing social media platforms like Instagram or Twitter may very well be protected by copyright, which means you really should have permission from the copyright owner to use it—unless what you're doing counts as fair use, which, again, varies by country.

Even on platforms that have systems like Content ID for detecting unauthorized use of copyrighted material, you're safest when you use and share material that you have permission to use; crediting the original creator, when you do so, is a good practice.