A long, long time ago, there was an online messaging tool called ICQ. You didnt even have callsigns in it, you had a randomly generated number you shared with your friends. You chatted. Had fun. Life was good.

Then there was AOL instant messenger. It largely replaced ICQ in the US. It added emoticons.

Then there was MSN Messenger. It tied into the MSN gaming zone(Before MS killed it to make Xbox Live. You could play games with your friends through it. You could do rudimentary video chats.

Then you had Skype(pre-MS. Better video, not tied to MS).

MS makes MSN Messenger into Lynx and adds it to office. Its not good.

Then you had Google Hangouts. Better chat, fun features, tied to your google account.

Then you had MS owned Skype as Skype for Business. Largely replaces Hangouts because Google enshittifies everything, not because it is good.

You also have former Vancouver startup Slack. Its fantastic. Until Salesforce buys it.

Now we have the bastard officespring of Skype for Business: MS Teams.