Conflicting icons are multiple icons that commonly represent a single concept. For example, to like a post on Facebook you’d use a thumbs up, but on Instagram it’s a heart, and on other sites, it’s a star. While you can use any of those icons in your design, the key is to be consistent and only choose one for your interface.

Conflicting icons can sometimes have different meanings on different sites. Going back to the heart icon, on Instagram it likes a post, but on Facebook it loves a post, and on sites like Etsy it will add a product to your favorites list. That doesn’t mean you shouldn’t use a heart icon. Just be aware of the different meanings users may attribute to it and make sure your usage is clear and consistent.