The private message was an inter mail, nice & private the conversations are pretty much the same but in thread format so you do not have to look up what someone is replying to. The old format was you needed 4 messages to have PM open to you I have read that that may have changed to 10 posts. Click on an avatar a box opens up & if you have privileges you will see start a conversation. If you particularly like what an individual has to say you can also follow them and when you log on you will have alerts to what the person has contributed. To follow a person used to be known as befriending them. If you should find someone rather offensive the ignore can be activated in the same manner.