Electronic mail or E-Mail allows users to send message across the Internet. The emails consist of the sender and recipients' addresses, subject of the email as well as the actual content body of the email.
Email addresses are designated locations on mail servers that are identified as destinations by email clients (applications like Microsoft Office or web applications such as GMail) & servers.
If you have an e-mail address, you can send mail to anyone who has an email address. It works in a similar way to the physical postal mail which has been used for centuries.
Modern email and webmail applications allow attaching any type of file to the text body of the email, thereby allowing people to send photos, documents or even video clips over the Internet.