Everybody is on Facebook right now and one of their features is Facebook Messenger which we can use directly from phone or computer where we can download separately from the web https://www.messenger.com/
From Android phone you can download from https://play.google.com/store/apps/details?id=com.facebook.orca&hl=en
However I don’t install Messenger apps on the phone or computer. The reason to this is I don’t want to attach with Faceboook as it can decrease my productivity when I am in work.
So I only use facebook from the web browser on the phone, and always ignore the offer to install messenger separately on the phone.