Multipurpose Internet Mail Extensions, or MIME, is a standard that extends the format of email messages to support text in character sets other than ASCII, as well as attachments of audio, video, images, and application files. It allows emails to include multimedia content, making communication richer and more versatile. MIME works by adding specific headers to email messages, indicating the type of content being sent. For example, a header might specify that an attachment is a JPEG image or a PDF document. This helps email clients understand how to process and display the content correctly.