Microfrontends are a way of breaking down a large frontend application into smaller, more manageable pieces. Each microfrontend is responsible for a specific part of the application and can be developed and deployed independently. However, there may be common functionality that is required across multiple microfrontends. To avoid duplicating code and to ensure consistency, a shared library can be used.

A shared library is a separate codebase that contains functionality that is shared across multiple microfrontends. This can include components, services, utilities, and other code that is used by multiple microfrontends.

The shared library is developed and maintained separately from the microfrontends and can be versioned and deployed independently. This allows for better code reuse, easier maintenance, and faster development times.