Electronic mail, or email, allows people to exchange messages over communication networks like the internet. While computers are most commonly used, other devices can access email as well. There are two main types of email - one that requires a network provider subscription and one called webmail that is accessible through a web browser. Email does not inherently ensure confidentiality, integrity, or authentic authentication of messages. Specific steps must be taken to protect information transmitted via email, as it offers a similar level of privacy as a postcard. Network providers must inform customers of their email and personal data management policies.