• When you send a message on WhatsApp or Telegram, one or two check marks appear underneath it, which turn grey to blue after a while. These check marks provide you with vital information, but if you're not sure what they mean in WhatsApp or Telegram, keep reading.
• The read receipt feature in WhatsApp is indicated by the check mark icons, which indicate if the other person has received or read your message.
• A single grey check mark in WhatsApp indicates that your message was sent but not yet delivered to the intended recipient. Two grey check marks indicate that your message was delivered to the other person's phone but that they have not yet opened it.
• Finally, you'll see two blue check marks below the message when the other participant has opened your discussion and seen it.

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