I'm going to tackle now something appart from class but has to do with communication: Emoticons.
Back when the first cell phones were made and when Messenger appeared, something new was created: Emoticons. Those are faces that represent people's emotional status. There were two types: On the cell phones, people normally used some alphabetic symbols that readed, looked like a face. For example: :-) . The two dots represents the eyes, the dash a nose and the closed bracket the mouth. That means that person is smiling. On Messenger, on the other hand, were actually faces that were shown when you wrote the legend
The legend of the default emoticons on Messenger. Source
