# Lists

Lists are static collections of Marketing Campaigns contacts. This API allows you to interact with the list objects themselves. To add contacts to a list, you must use the [Contacts API](/docs/sendgrid/api-reference/contacts/add-or-update-a-contact).

You can also manage your lists using the [Contacts menu in the Marketing Campaigns UI](https://mc.sendgrid.com/contacts). For more information about lists and best practices for building them, see ["Building your Contact List"](/docs/sendgrid/ui/managing-contacts/building-your-contact-list/).