Voicemail is a system that records phone messages when you can't answer a call. When someone calls and you don't pick up, they hear a greeting (often your voice saying something like “Hi, this is Sarah, please leave a message”), then a beep. After the beep, they can talk, and the system saves what they say as a recording you can listen to later.

Before voicemail, people used answering machines: small cassette tape recorders that sat next to the telephone. Voicemail works the same way but stores recordings digitally, usually on your phone company's computers or inside your cell phone itself. You can listen to your messages by calling a special number or tapping an icon on your phone.

Just like regular mail arrives in your mailbox, voice messages arrive in your voicemail box. Today, many people prefer texting to leaving voicemail messages, but voicemail remains useful when you need to explain something complicated or when someone doesn't use texting.