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Telegram (informally abbreviated as TG or Telegraph) is cross-platform instant messaging software whose client side is free and open source software, but whose server side is proprietary software.
Users can not only send messages, pictures and recordings via Telegram, but also enjoy a variety of security options. It uses end-to-end encryption, so all chat content (including attachments) is not transmitted through the Telegram server and therefore cannot be seen by third parties. It also offers a "burn after reading" timer, which means that private messages will disappear after a certain amount of time.
The company, founded in Berlin with just 45 employees, is now operating worldwide. It has been a huge success in Iran, with over 2 million downloads, and has been well received in Ukraine, Russia, Saudi Arabia, the United States, Brazil, India and other countries.
Prior to founding Telegram, Pavel Durov was the CEO of VK (formerly VKontakte), Russia's largest social networking site, where he was forced to move to the United States after losing control of his former company. Subsequently, he announced that he had created the Telegram application for his brother.