What do the check marks in Facebook Messenger mean?

Most users nowadays use the Facebook Messenger app to communicate with their facebook friends. Maybe you are one of them. Also, you may wonder what those new check mark symbols represent. Has the user read the message i sent him? Will it be delivered? etc. Below, we answer those questions by explaining how the new messenger's system works.
Let's say you type a short message and you hit "send" to deliver it to your facebook friend. Here is what happens. There are 3 scenarios.

1. If the message you sent is delivered by the other user's device then you will see a check mark in a filled-in blue circle just like the one in the picture below.

2. If your message is sent but it is NOT delivered by your friend's device you will see a check mark in a blue circle NOT filled-in this time as the next image illustrates.

3. If you see next to your message a small circle with your friend's face then it means that your friend got the message and read it (message seen). This case is shown in the photo below.

You might also want to check this post about how to turn off chat for certain friends.

Do you have other questions about Facebook Messenger? Ask us in the comment section below and we will be glad to answer them. As always, have fun.