Email messages are digital communications sent over the internet using electronic mail systems. They typically consist of a subject line, a body of text, and can include attachments such as documents or images. Users can send and receive emails through various platforms, including web-based services like Gmail and Yahoo Mail or desktop applications like Microsoft Outlook. Emails are widely used for personal and professional communication, allowing individuals and organizations to share information quickly and efficiently. They can be sent to one person or multiple recipients, and features like CC (carbon copy) and BCC (blind carbon copy) help manage group communications while maintaining privacy.