In British English it is the full stop; in American English the period. This punctuation mark has been used for centuries to end sentences. Its use is changing today. A report says the full stop is "intimidating" to young people. They view it as a sign of anger. This is especially so on social media, where many youngsters largely do not use punctuation, except for lots of exclamation marks!!!!! A famous linguist said: "Usage of full stops is being 'revised in a really fundamental way'. People simply do not put full stops in, unless they want to make a point."
Linguists studied how technology is changing language. One said: "If you send a text message without a full stop, it's already obvious that you've concluded the message." Young people tend to look at finished text messages with full stops as being insincere. A journalist wrote that a full stop is "simply not necessary". She said: "It's clear when you've finished your thought, so what function does the period fulfill?...Using a period in messaging...can come across as if you're quite cross or annoyed." She added full stops are now being used to emphasise single words.