Peer Dependencies is a dependency relationship indicating that the dependencies should be provided by parent in the dependency tree.
They are provided by the parent. ie
It indicates that:
They model a parent-child relationship
In Javascript Package - Package.json, they are declared in the peerDependencies property of the package.json file.
yarn add [package] --peer
Bundler - You may have to change the configuration of your bundler to exclude them. Example webpack