A family of Microsoft word processing software products for creating web, email, and print documents.
When you copy content which is formatted in one or more paragraph (or character) styles, the default behavior is to add the styles, unless they already exist in the target document.
When a new style is copied into a document, its settings, including priority and presence/absence from the Quick Style gallery will also follow along.
To prevent styles and/or formatting from being added, you can paste as unformatted text. You can use the Keep Text Only command on the Paste Options button.