Short messages, also known as SMS, are a form of communication that consists of brief written messages sent via mobile phones or other electronic devices. They are typically composed of no more than 160 characters and can include text, images, videos, and audio. The two crossword solutions for the term 'short messages' are NOTES (5 letters) and LINES (5 letters). NOTES is an acronym for 'No Obligation To Enter Service, ' which is a type of SMS service that does not require a subscription. LINES stands for 'Limited Interchange of Network Elements, ' which is a protocol used to send SMS messages between networks.